EDIT: Just crossed 26000!
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.
Source: https://lemmy.fediverse.observer/list
Exciting to see all this growth!
So, it is recommended to either join one that fits your niche or maybe to self-host?
Maybe join a big one for general content and then supplement with smaller, niche ones.
I'm confused, why does it matter? Can't you view all content the same regardless of the instance you're on?
Yes, you're absolutely right. Once you understand how to subscribe to communities in different instances, it doesn't matter much. But new users may not be familiar with the process yet, and I (probably wrongly) assumed that you were one of them. That's why I suggested the option that worked for me until I figured out federation.