Why do people consider Al Jazeera as a trusted source?

I'm not sure I consider them a trustworthy source per se. I don't think they're necessarily less trustworthy than the BBC. BBC is propping up a Western colonialist perspective. (Not trying to beat up on the Beeb specifically. Major trusted U.S. news sources tend to more specifically support U.S. nationalism ... even the "liberal" ones.)
I think if a viewer / reader in a Western mindset, the difference in the blind spots between Al Jazeera's perspective and Western media will complement each other in a way that will give readers / viewers a more well-rounded perspective on history. At least as compared to sticking only to Western perspectives.
- Very well-put. AJ helps me get the ‘Eastern’ perspective of world events, which can get sanitized by the West. Taking the Gaza War as an example, BBC/any US media outlet is almost always going to take a pro-Israel bias—even inadvertently. I think it’s important to hear from groups who don’t have incentives to portray israel in a good light. Again, tho, that’s one example, and you should always consult multiple news sources.

Cherry pick a few topics you know incredibly well and look at their published articles on those subjects.
Did they cover your area of expertise correctly with nuance and giving the appropriate context?
If yes, now you have more confidence that the articles in other areas are also well written and researched.
If no, now you have less confidence in them
You can apply the above strategy to any news source. For many people the above protocol gives good results with aj.
- Cherry pick a few topics you know incredibly well and look at their published articles on those subjects.
  If they ever write an article on the In N out secret menu I'll let you know

Every news source has bias, Al Jazeera has over 3000 staff, over 400 journalists and access that comes along with being that massive of a news agency. Obviously they are biased towards reporting that favors the government of Qatar who funds them. Particularly if a lot of stuff is happening in the middle east and Al Jazeera has more journalists in those countries with better connections to those countries they are gonna be first to cover a lot of things in the region. They are also much less likely to use passive voice and other qualification when talking about things like Palestine in their reporting. A lot of people don't want to read "50 Palestinians are shot" instead of "IDF battalion kills 50 Palestinians".

usa based media as you know leans right wing, all of them, and many of them are owned by right wingers irl. if you look at how they glorify the military and vets, and have copangada type shows. it almost never discredits a right wing president in a very negative light, while same cannot be said if it was Dem in power. certain things you notice you really cant criticise, is israel, CHRISTIANITY in movies, and shows, and military. everything else is ok.
AJ may not be neutral source, but its a source that is not controlled by the west, so you might get a ME perspective. just like how some british media reports some truthful news in the USA that usa would sugar coat or downplay, but not against british based news.
asian sources heavily criticizing usa for involvement in thier region, while usa never ever does that.
- Yeah going around saying "thank you for your service" to "veterans" you don't know is crazy IMO.
  
  It kind of makes sense in the US, because the US is CONSTANTLY at war with someone / something, so unless people volunteer, there's a good chance the draft would be back and a bunch of people would be forced to go.

It's not about being exactly more reliable than the other big ones. More about being a second perspective, filling in the gaps of the western ones.
- Yeah, read a couple of sources and take the average.
  Always bear in mind who funds it.
  
  Be careful with the taking average mindset. It's a default human one, and it's being abused. A lot of media outlets (particularly American right wing) are mouthpieces for the same few groups or people.
  Instead, try and look at their biases. Do they have a reason to mislead you. What akin do they have in a particular game. E.g. the BBC is still fairly unbiased on a lot of world news. They are far less unbiased on middle eastern politics now.
  It's an annoyingly complex problem to solve, on the fly.

How about you give your supported and and reasoned opinions for why it is an untrustworthy source?

A pretty long track record of high-quality journalism. Same as the BBC.
Sure, they're owned by Qatar. As of last I checked it serves as more of a status symbol than a propaganda outlet, though, at least in English.

Al Jazeera is funded by the Qatari government. Make of that what you will.

Like any media it is legit at certain topics and not at others

Imo it's not about saying this or that org is least biased or less biased, it's acknowledging the biases present in all news orgs and comparing the reporting from multiple sources.

Even if you don't like al jazeera, remember they're some of the few who cover Gaza in person and a whole lot of Africa and other developing nations. I don't blindly trust them, but many western news agencies are barely reporting on the same thing. If they're not covering these nations, why are we complaining about one of the networks that do it?

You made this a question about Al Jazeera but I think at the same time it should be a question about you. What type of media are you trying to consume about what topics with what goals? Depending on that answer, the utility of Al Jazeera to your life would massively change.
One general approach to understanding national domestic policies is to read one or two papers from your country and then to read one or two papers from a different country, or preferably two different countries, and see how the information stacks up. if you want English language media, maybe you have something like BBC and then ... Gosh it's hard to think of any decent US newspapers ... Seattle Times? ... Maybe something Canadian, and then maybe something Qatari? Why not.
That type of media consumption avoids some common pitfalls, but it's not perfect. Most mainstream media outlets tend to be pro-establishment, whatever that may mean.
- Not sure why you're being downvoted for providing good advice about avoiding media bias.

Why wouldn't they?
It's hard not to interpret this comment in a western chauvinistic light.

This kind of question is similar to proving a negative in logic.
You're asking why people think it's trustworthy, implying you believe it isn't.
*Which people think it's trustworthy? You used an ambiguous "many people" - I'd need to see something supporting this assumption.
It would be more useful for you to give examples of why you don't find it trustworthy, as this is what really matters with regard to any source.
I don't trust any one source, and instead try to piece together a likely truth by considering the different sources and how a story is told. I'm surely wrong as much as I'm right, but it's the best any of us can do.
- The question asks for reasons people who consider it trustworthy do so. That's nothing like trying to prove a negative. That's just giving input on why you (may) believe something different from the asker.

Scepticism should always be applied to any state-run media.
- Private media is not any more trustworthy than state run.
  
  Please refer to the other comment where I address this.
- Is it better for media to be privately owned by billionaires?
  
  No, definitely not. I don't think there is any news source I would trust 100%. You need to seek out multiple sources and try to sus it out yourself. The truth is usually somewhere in the middle. I don't claim to have all the answers but in my experience state media tends to be less than trustworthy. I'd say BBC is okay but they've had some big fuck ups before.

As we quickly learned during the George W Bush era, no news media agency can be trusted. To counter this, check reporting of the same incident from multiple news agencies and find the consistent facts. Everything else is suspect.
In a hurry, see if Reuters or AP has covered it, but verify when you have the time.
Done this way AJ is perfectly viable as a source for news, in that the bias can be filtered out.
FOX and OANN are known to lie or misrepresent facts entirely, but that gets filtered through cross-checking.
Trust, but verify.
- Well...Anyone has an agenda.
  Even the most passive person when put in charge will have a personal philosophy they'll follow.
  
  You’ve been on this account for two years. Happy birthday

Can't speak to anything but Al Jazeera America. Short lived, but they promised unbiased news. And gods was it unbiased, flat as paste. Really woke me up to how I'd come to expect entertainment in my news and not simple facts.
- News shouldn't be entertaining; it should be factual and unbiased.
  
  almost all the current MSM in usa, is entertainment, they are basically fox-lite, so its heavily sensationalized, or basically a tabloids to get click and viewers.
- there was an asian source that was very similar, flat and unbiased, but i forgot which one was it.

There's a saying among BBC journalists that all who work there eventually end up at Al Jazeera.
Watch one of my favorite documentaries of all time, Control Room (2004) about coverage of the Iraq War.
Al Jazeera is far from perfect, and I'd argue has fallen from its peak in terms of quality. But it's still worth viewing to get a more well rounded perspective.
Now do I believe they can cover topics that hit close to Qatari interests? Not necessarily. For those I take with a grain of salt.
- How so? Higher wages/ better benefits compared to BBC?

You need to receive news from a broad variety of sources, not just those that agree with your viewpoint or have a particular agenda.
Al Jazeera obviously have a pro-Qatari but less so than Fox News for example or any billionaire owned newspaper/TV channel have biases.
Aggregate from all sides and the truth will be somewhere in the middle.

Their original staff was a bunch of pretty serious journalists sourced from the BBC.

Its a large organization. There's Al Jazeera, and then there's its Al Jazeera English subdivision which operates with widely different team. The latter has a reputation for high quality journalism and has won multiple awards for it - the former exhibits more bias in its reporting.
https://en.wikipedia.org/wiki/List_of_awards_awarded_to_Al_Jazeera_English
I would say the BBC is no more trusted and should not be any more trusted than AJ English. Each have biases and each are capable of very high quality investigative journalism.

I have been wondering about this for so damn long....

Becuase it was founded with the same journalistic practices as the BBC.
- Sounds very middle eastern.
  Based on the name alone I assumed it was something like Bloomberg (I believe they do financial/world news) and state media from some middle eastern country.
  Please keep in mind that I don't watch any domestic traditional TV and at best some clips our local media network uploads to theirbrespective youtube channels.

In my life experience the only way to test the reliability of a news source is to actually live some events and see how they are reported by different media.
I have no such experience with al Jazeera, so I couldn't tell you reliably if they are or not reliable. Best advice with media is, unless you are certain they are reliable, treat them as unreliable.
- reporting from "outside looking in" perspective, rather the us/bbc which only does it in the inside looking in.
  
  I'm not American. bbc is also a external news source for me.

There are places (Ground News is a good one IMO) where you can see how biases are broken down by factors like factual accuracy and political alignment.
- I check my 5 free articles on Ground News practically daily. Ugly site. It points out some ugly things about us.
- how biases are broken down by factors like factual accuracy and political alignment.
  Which they determined based entirely on their own biases.

Does anyone have a link to the bbc paywall thread?

Yes, Al Jazeera is biased. But way less than other news sources in the area, and way better than many large American "news" sources.

Al Jazeera is the mouthpiece of a hostile foreign power (to me). Its also sickeningly, cloyingly coated with hate for the US throughout any segment. I will on occasion read something that's been generically reposted, recognize the writing style, and then confirm that it came from AJ. Its so tilted that it reminds me of Fox News. And I don't watch Fox News either.