Mastodon

And it wouldn't have been a problem at all if accounts, their history, content, identity, relationships and reputation were seamlessly migrateable between instance. Whatever happens, you could just migrate to your own personnal instance.

But right now, while you can copy your old bulk text, you basically lose everything from what little of a migration you could even do.

All relationships are lost and you start back at square one. And that's what makes choosing the right server important and that's what bounces people right off mastodon and lemmy.

And it also drives re-centralization because one way to side step the problem is "just join the biggest instance"