As a long time Reddit user, there's something about Lemmy and the fediverse that feels really refreshing and new. I think it has to do with a few things...
People are more respectful of each other and interested in discussion and being social.
Less trolls (users are probably older?)
Due to it not being absolutely huge, I feel like people will actually see my posts and comments instead of being lost in a sea of content. I suppose once Lemmy grows this will change, however the cool thing about the fediverse are the new servers. So you can stick to the server when you want smaller community discussion and go to "all" when you want more populated threads.
The clean UI feels refreshing and clean, almost like the early internet.
What have you noticed? Do you find it refreshing too?
I think it's partially attributable to Lemmy phone apps haven't taken off yet. Phone posting is a different medium than desktop posting with regards to McLuhans "the medium is the message" principle. Phone usage appeals to the lowest common denominator. People use it as a time waste to mindlessly scroll. The cognitive load is much lower. Thus shitty content bubbles to the top because that's all the brain power people are giving it. Phone usage is not conducive to consuming depth of content nor contributing it.
Additionally I think the lower cognitive engagement tends to lead people into greater fuckwad behavior. You aren't on a board with human beings on the other side of a keyboard. It's just a stupid app on your phone.
I think if I'm right then in time Lemmy with death spiral not unlike reddit if phone apps mature and Lemmy apps become a mainstream daily use type of affair. I doubt that will happen without the capitalist engine driving it though.
I don't actually think it's got much to do with having a phone app or not. I see what you are saying with the medium being the message, but I don't think the "medium" is phones or computers.
You're right about the medium being the message though, it's just that the medium is a nerdy federated social media. Right now we are in the first or second big wave of new users. Not quite the nerdiest of the nerds who would have been using Lemmy since the beginning, but we are getting the "early adopters" and the people willing to go out on a limb to try something new. These are the kinds of people who are likely to interact with a community in a positive way, because they are already investing themselves into something before it is established.
I am using a phone app to write this message right now, it was really easy and accessible for me to login and get to grips with the UI. There are loads of people just like me, in fact I would be willing to bet Lenny is being used by 80% mobile users. It's just how we communicate with the world these days. Very few people browse social medias on a computer.
You're also forgetting that with a centralized platform everyone is stuck under the same roof. If we do reach that level of saturation then the communities can always splinter into a different instance or group of federated instances.
The problem with reddit was once we reached the point of everyone being there and the overall quality lowering, there was no refuge for the more engaged users to congregate and reform the communities that focus on quality over quantity. You could try and flee to more niche subreddits but it's really not the same, as demonstrated by OP making this post.
And then as you pointed out, the financial incentives are very different here, which will change how users engage with the platform and how the platform evolves as a result. Centralized platforms do everything to drive engagement to increase ad impressions and potential value to ad distributors. We have an opportunity to build communities with entirely different business models where growth is not an imperative.