Adding to the thread of account redundancy and backups based on personal experiences...

I started I think it was on .ml or .world, quickly found kbin.social and preferred it, it died and I didn't have a culture of backing up accounts, then I moved to lemm.ee and I kinda forgot to make a backup in the grace period before it died (oopsie) but at least had been hoarding on RSS feeds so not all was lost, then found Mbin was a thing, then found about external RSS's and searching for fediverse links for pulling external posts.

Adjacent to external RSS's, also found out when an instance goes poof, the community/group/magazine keeps propagating, just as a derelict one. So while it'd be a moderation hell, at least it's somewhat preserved.

So moral of the story, there are a few ways to back stuff up, and thus, adding to the choir, please do use them.

And an addendum, PieFed also has external RSS feeds by default, so for example, piefed.social provides their own RSS feed for !fediverse@lemmy.world.