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!
I would not be surprised if lemmy.world will outgrow lemmy.ml this month. Lemmy.world has a lot of active communities and meanwhile lemmy.ml. is not allowing new registrations and many of the existing communities look like they are no longer maintained or used.
lemmy.ml seems to be mostly memes at this point