I'm on Mastodon, same name as Twitter. (And Pillowfort and CoHost, though i don't use them regularly).

Bluesky is owned by Jack, creator of Twitter fame. I won't go there because he is problematic himself and I can't trust that he won't sell it to yet another billionaire that'll run it into the ground.

There's another one, run by a Christopher Bouzy, that is also problematic. Won't go there either.