Now imagine that you had some issue with the administration of your Lemmy instance. You still have both options above, plus a third one: migrate to another instance.

In theory, yes.

In practice, I strongly disagree with a number of decisions by the admins of my instance, but I’d rather keep ownership of the comments I have posted and would like to be notified if anyone ever replies to them in the future. Since I care more about the latter than the former, I’m not planning on moving instances at the moment. Guess I could create another account elsewhere, but I’d still have to check out the account on the old instance every once in a while. Plus I’d like to have a unified posting history. It sucks, and the technology is not quite there yet, but I hope true migrations between instances become a thing sooner than later. As far as I have been told, true migrations aren’t yet a thing even on Mastodon.