I don't think it's quite stable. The external events that caused waves of new users to arrive from X are getting rare and bringing in fewer. When those aren't happening it's been a slow, gradual decline.

Some people are getting introduced to similar and in some ways worse UX on Bluesky now that there are some actual efforts to make it slightly less centralized.

I believe that surge was Elon announcing AI image editing on X and a bunch of Japanese artists and their followers trying out Bluesky.

I'd rather say Twitter and Threads are the current winners if we're talking about userbase. Bluesky is basically in the same league with Mastodon while those two are so far above that you can't even see them without a telescope.

This actually manages to be worse than either of those two things. It isn't a separate service from Bluesky but it also doesn't really offer any meaningful decentralization.