Part of the problem is you don't understand how containers work. If you need to do a 'container wipe' and starting from scratch, you're doing it wrong.
I've been running nextcloud in k8s for years and running a few occ upgrade commands after an upgrade is annoying but not the end of the world.
Yeah, exactly. If you're starting over from scratch constantly you're doing something wrong. Check out https://docs.docker.com/storage/ for a few options on how you should be managing your storage.