I was an early adopter of Blue Sky--joined back in 2023--and I haven't had a single regret, unlike with some OTHER social media hellscapes that I won't mention *coughxitterfacebookcough*. There's NO algorithms as far as I can see, everything is open source and done via interactions with other actual people, and toxic troublemakers are actually blocked or booted. It's nice and growing pretty fast, with about 32 millons users so far.
Mastodon is similar, but less well known, likely because it's more federated and was slower to adopt a pseudo-Twitter interface everyone was used to. It's still very active depending on the server you join (mastodon.social is the most popular) with about 9 million total users.
Plus best of all, there are tons of creators to follow on both platforms--artists, writers, musicians, etc. Follow me and others on both platforms!
https://bsky.app/profile/plucas.bsky.social