Mastodon has been around since 2016 and has 804k MAU.
The platform has 57 third party apps.
The platform is decentralized and has community ran servers.
Personally, I’m excited there’s a decentralized option that’s super popular. Yes, relatively very few run their own PDS, but if the main bsky instance becomes a problem for anyone, people can easily migrate.
It’s not just data ownership either; The AT protocol supports community-built algorithms, relays, and app views.