Actually… From a data-loss POV, it’s actually pretty much fine; since the server only serves an e2ee file anyways, each end device’s data is sufficient to recover everything.

I.e. if you host Vaultwarden, log into it on your mobile device, save all your logins; then fuck up the server, it doesn’t matter, because your mobile device not only still has everything, but also does not need a server connection to export everything in a way that can then be imported again on a new server installation.