You seem to be describing hosting your own service, changing the underlying hosting provider, and tying your identity to ICANN DNS.

There are two separate things here, identity portability and data portability. If your identity is portable (say a key pair) but the service hosting the data goes down and you don't have a backup or there's no way to import the data to a new provider then you've got a problem. Similarly, if the service goes down and you do have a backup of your data and a way to import it to a new provider but your identity isn't portable (perhaps it was user@domain and you don't own the domain) you also have a problem in that case but it's a different problem.

And neither data nor identity is the same as account, at least the way I was using the words.