Someone around here recently linked to this two-second explanation explaining why they wrote Bluesky.
With ActivityPub the Fediverse has us all counting on instances.
Sure, we can sort of change from one instance to another, but it's a kludge. We don't really move but rather start a whole new account and set up a note on the old instance pointing to the new one, IF the old instance decides to cooperate. See how tied we are to instances here?
I always thought this was a huge issue, a huge mistake in the core design of ActivityPub, one that can't really be changed at this point.
Bluesky does this better, putting the power in users' hands and allowing users to actually move from one node to another, decentralizing all the way down to the user.
https://github.com/bluesky-social/atproto/issues/255#issuecomment-1287953987
