You can still use your vault when the server dies, you just can't sync it across devices. Worst case you can even export the vault in your local device if the s

You can still use your vault when the server dies, you just can't sync it across devices. Worst case you can even export the vault in your local device if the server never comes back up. For other services (matrix etc) down time is very bad but for vaultwarden I don't see it as such a big issue.