The platform crossed the milestone last night, and it happened about a month and a half after the 25 million mark. Bluesky still has a long way to go to pass Threads, though; Meta’s platform has more than 100 million daily active users.
[Media: https://bsky.app/profile/bsky.app/post/3lgu4lg6j2k2v]
The difference is that you can easily move to another Mastodon instance, and it’s designed so that when you do that your followers / followees come with you.
Except you can’t move your posts. Or, really, anything other than followers.
True, and this is something that Bluesky actually seems to do better. Your posts are stored in a “PDS” (personal data store), so in theory they’re not tied to any particular instance.
I hope that a future version of the Fediverse design / ActivityPub considers how to handle this issue. Still, I’d much rather lose my past posts than lose my social graph. Past posts can probably be archived, but it’s much harder to track down people you used to be mutuals with on a different account and follow each-other.