Today I learned hyphenated words are largly obsolete

"Printed writing is very much design-led these days in adverts and Web sites, and people feel that hyphens mess up the look of a nice bit of typography," he said. "The hyphen is seen as messy looking and old-fashioned."
I see the dictionary editor they quoted is still fighting back.

That's a sweet ass-car
- Good ol' #37.

You mis-spelled “to-day”.

there are times when punctuation is actually useful for clarification!
- And capitals for readability.
  
  yeah, without them capitalizing that first t their comment is completely unreadable
  
  hyphens are dead, capitalization is next.
- They can rip “E-mail” from my dusty old hands!

I like to use them when words create a unit of thought. Like line-of-sight, and such. It really helps readability. It prevents people from having to think too hard about certain sentences when it's ambiguous which words belong to what part of the sentence. Especially when the expression contains function words like "of".
However, I'm a fan of just making multiple words into compound words, like bumblebee. That doesn't work well with something like lineofsight, though.
As a side note, I wish we would bring back the diaeresis in favor of hyphens in words like co-op. It used to be coöp, and that is so much more fun. Or words like reëlect. Even when it's not abbreviated, the diaeresis makes it more obvious to readers how coöperative is pronounced. Or any other time where two vowels in a row are pronounced separately.
- Albeit always confuses me. Albeït is so much better.
  
  Sobeit
  
  Albeit comes from all-be-it?!?!?!?!?!??! You just blew my mind!
- Would the dieresis be placed on top of the s in lineöfsight? Or would it be for vowels only?
  Also, by your coöperative pronunciation example, people would be mispronouncing reëlect.
  
  It's vowels only, and that's funny. I hadn't thought about it for my hypothetical "lineofsight" word.
  
  Also, by your coöperative pronunciation example, people would be mispronouncing reëlect.
  I'm not sure what you mean.
  It's pronounced co-operative and re-elect. Coöp needs it to not sound like "coop" as in chicken coop. Reëlect needs it to not sound like "reel" as in fishing reel.
- I think you would be more convincing if you spelled "line of sight" correctly
  
  Good catch. I fixed it.

I'm gonna argue with the title.
Obsolete means no longer of use, in a general sense.
Just because people don't know that the tool is there, or don't know how to apply it, doesn't mean it's obsolete. Hyphenation still has its original utility, it helps communicate in writing what is evident in speech.
I get what they mean, but the title is not accurate to the rest of the article, imo.
- Tell that to Word it always wants to auto contact my words to do that.

they are a bit old-fashioned

A question from a non-native speaker: Is there a definitve guide on American punctuation somewhere? I always wonder about American use of punctuation inside single quotes when quoting a term instead of a sentence, and some other cases where I see different intepretations of punctuation.
- There are different ones for different kinds of writing (general, academic, journalism, and more). Chicago Manual of Style is one of the general ones. It's good, and considered authoritative, but you have to buy a copy or an online subscription.
  A free one that I like is Purdue OWL (Online Writing Lab from a university). It's easy to understand and has good info.
- The most commonly used tool for referencing English grammar that I know of is The Elements of Style by Strunk and White.
  
  I've heard it being a bit snobbish and outdated, despite having newer editions, but I will look into it. Thanks for the tip.
  
  That takes me back. That was the standard reference for my journalism degree 35 years ago. I still have it.
  
  That's good for some general writing tips, but S&W made plenty of their own errors in the book and had ambiguous or wrong explanations for various topics (IIRC they don't seem to know what passive voice actually is).
  I wouldn't recommend it for someone looking for solid info about grammar itself.
- I found this. It seems pretty good. Although I don't really think it matters much. You'll likely be understood the same.
  
  Thanks. I think it is quite well made, and I would love authors read this before they hand in their manuscripts...

Take a second to actually read this one. It's pretty short and sweet. It's also from 2007, and talks about nouns (maybe compound nouns) that we really don't think and probably never knew were hyphenated. It's not about the use we typically see today.
As an aside, I've noticed people start hyphenating in weird ways, like "I've been at this job for 7-years"
- I think at this point MS Word automatically recommends a hyphen after any number + quantifier combo. One time it wanted me to correct "three armed guards" to "three-armed guards" which would have changed the meaning considerably.
  The number of times MS autocorrect suggests incorrect changes to grammar is laughably high, and most people just blindly follow the suggestions.
  
  I fucking hate autocorrect. I mean to say "its" a lot more often than I mean to say "it's", but Gboard on my phone tries to change it to the latter almost every time.
  I say "almost" because it did it the first time in the above sentence, but not the second time, so it managed to make the wrong guess for both of them. Goddamn useless trash -- Markov can suck it!
  
  Three-armed guards would probably be in very high demand, depending how functional the extra arm was
- Could the strange hyphenation be due to the influence of their mother tongue? I don't know if there is any language that does it like that, but it seems plausible.

Special characters suck in on-screen keyboards, and the bastards rarely gave us physical thumboards.
- Special characters suck in on-screen keyboards
  Not as much as they do on physical keyboards with their “hold alt-gr and hope” approach.
  
  My favorite phone was the Galaxy S Relay, which featured a sliding, 5-row thumbboard. Numbers, letters, period, comma, and question mark were all available without alt or fn keys. The number row had !@$#%^&*() with the shift key, just like actual keyboards.
  It even had four arrow keys for cursor navigation!
  I absolutely loved that phone.

is old fashioned non-hyphenated?
like red tree
- My experience is more "feels" than fact I suppose, but I've always seen it that any adjective or noun playing adverb to another adjective or participle should be hyphenated to the word it describes.
  Red-hot coals (coals that are hot to the point of being red)
  Red hot coals (coals that are both hot and red)
  Ruby-red shoes (shoes that are as red as rubies)
  Ruby red shoes (ruby shoes that are red)
  Smooth-talking rogue (a rogue who talks smoothly)
  Smooth talking rogue (a smooth rogue who talks)
  Bamboo-eating panda (a panda who eats bamboo)
  Bamboo eating panda (bamboo is eating a panda)
  
  ruby shoes that are red
  You mostly nailed it but this one would be “red ruby shoes”
  determiner, quantity, opinion, size, physical quality, shape, age, colour, origin, material, type, and purpose

*To-day

You should use replace the - with space or nothing at random
icecream ice cream ice-cream
- Nah, just turn the first word into an adjective.
  "Iced cream" sounds far more sophisticated than boring ice cream.
  
  Hmm, marshed mellow ...
  
  Or add - to words that don-t need-it
  Iced-cream

- You think we (Americans) are smart enough for that?

So English has been devolved by vapid influencers anew.
- Language purists are veebs. Communication changes. The definition of language is descriptive, not prescriptive.
  
  Depends on the language, the context, and the application. Sometimes language IS prescriptively defined. Language is more than just casual speech.
  
  Veeb isn't a real word.
- Some of those I've never seen hyphenated in 30 years of being an avid reader. And some of the corrections I see listed, I've seen used the other way.
  But I'm sure they read more broadly than I do.