My instance lemmy.one was down with no status updates for several days. And made realize that I'll probably need multiple accounts should an instance I use disappear. Or a more feature rich accountless experience if I decide to just wait for my instance to come back online as I lurk on another instance.
So seems useful to be able to have a subscription feed and filter list that can function without an account, which would make swapping accounts be a more consistent experience in the event there is a need for account migration due to instance being down or completely disappearing as some people have already experienced and lost their sub list in the process.
Like example of an app with a good accountless experience is Stealth for Reddit. It has no account sign in, but lets users have a personal subscription feed and save function which can be exported to a json file.