Almost! At the time of this post, lemmy.world has a whopping 25733 users and is growing fast.
Since my last post yesterday, it has added 4000 new users, making it the clear second-largest lemmy instance out there. Also quickly catching up to lemmy.ml's 36000 (not taking new signups).
beehaw.org (3rd largest) sits at 12500 users, partly because of more restrictive registration requirements.
While this is indeed awesome remember that the whole point in federation is having a lot of small communities rather than one or two huge ones.
In large part the same also happened on mastodon where mastodon.social has 200k people. This is not the way that ti's supposed to work; no single instance should have this many users, in fact often it's better to have instances for maybe 50 users at most
Anyone who is really hoping for the "fediverse" (fuck me I hate that name) to actually play out that way is delusional. 99.9% of casual users don't care about federation, they care about convenience. They want to go where the people are. This was always going to happen to federated sites as they get big, one will win out as the most popular. As you said, happened with mastodon, will happen here, will happen on any other federated service like peer tube or whatever it's called.
I'm mostly focused on going to a place and seeing lots of posts and comments. Behind the scenes, the tech that powers it? While I'm interested in it from a tech stand point, most regular people just don't care.
you're right that a large majority of people do not care, but this mentality will begin to change at some point. Also, the entire point of this is that it doesn't matter where the users are, because they can still join the same communities. Now, there are obviously a lot of things that need to improve in lemmy to make it more usable, but federation isn't one of them. The ActivityPub protocol is simple, yet powerful and relatively scalable.
Yeah, combine that with folks not understanding while registering that you can still see things from other servers while registering. They may kick the big one thinking it means they'll see the most content.