Comment by dewey
Providing robust restoring and backup systems for a system that allows to run any kind of workload is almost impossible. You'd have to provide database backups for all versions of all databases, correct file backup for the volumes etc.
It feels much more dangerous to have such a system instead in place and provide false sense of security. Users know best what kind of data they need to backup, where they want to back it up, if it needs to be encrypted or not, if it needs to be daily or weekly etc.
ZFS. Snapshot the entire filesystem, ship it off somewhere. Done. At worst, Postgres is slow to startup from the snapshot because it thinks it’s recovering from a crash.