It works a bit like "cell-phone number portability" in the US. You set your original account to point at your new account, and you tell your new account about your old account. All of your followers migrate to your new account automatically.
Of course, you could still get burnt if your host just disappears one day, because it can't point to your new account. So there's an incentive to use a well-run server with a good track record and a reasonable funding model, I guess.
In order for that migration to happen, the original server needs to cooperate and publish a "this person moved their account" message of some kind, right? I wonder if instance admins ever prevent that from happening if they don't like the server you're moving to.
I guess the problem is your username, right? Someone with a distinctive username that is, essentially, their identity has an incentive to squat on that username on multiple instances.
It works a bit like "cell-phone number portability" in the US. You set your original account to point at your new account, and you tell your new account about your old account. All of your followers migrate to your new account automatically.
Of course, you could still get burnt if your host just disappears one day, because it can't point to your new account. So there's an incentive to use a well-run server with a good track record and a reasonable funding model, I guess.