There's rarely any reason for not being able to shut them down, because you can trivially replicate. E.g. I've built systems where the only global piece of data

There's rarely any reason for not being able to shut them down, because you can trivially replicate. E.g. I've built systems where the only global piece of data was which backend held which user, and that data was trivially lazily updated via gossip-style protocols. Login requests were broadcast, and the backends responded, and the central services acted only as "backups" storing the most up to date info seen in case a backend happened to be unavailable. The whole thing was trivial to set up. (And you can back up sqlite "live" just fine with some care if you want to, or things like litestream).