Yeah it's the issue with this 'middle ground' of federation. some ideal world would be fully p2p, identities fundamentally would rest with the user's device or backed up somewhere public and encrypted, then servers just become meeting hubs or caches of content. there's some protocols that already do this at a technical level, secure scuttlebutt and nostr are two. there's other issues that crop up, for one moderation and content discovery starts to be a lot more complicated.

so, not a solved problem by any means, but federation at least gives us a bit more freedom than a singular centralized service.

In mastodon, you can move your account into another server. Technically it just copies your accounts, disables the old one and instructs all people following you to follow the new one. Here we don't have the "follow" problem, so less hassle, but not clear what happens to the communities of a shut down instance. Do they stay cached in other lemmies, but unable to post more into them?

I don't know if there's a community transfer feature though

The same holds true for monoliths like Reddit and Facebook and Twitter. What if they decide to just turn it off? In those cases you just lose everything. Period. With the Fediverse, if one instance turns off, then we just lose the stuff on that single instance. Everything else you have been following or doing is still there.

By and large, though, Fediverse instance operators are a communicative lot. If things are going to go south and the instance is going to go away, my experience has been they'll give you plenty of warning to move elsewhere and work to preserve whatever data you would like to keep.

Yeah an easy way to migrate/backup accounts would be nice. Also a way to backup communities so all of the content doesn't get lost.

You post and comment histories would likely still be saved on any instances that federated with them previously, I would imagine.