Apart from just peace of mind from bitrot, I use it for the snapshotting capability which makes it super easy to do backups. You can snapshot and send the snaps

Apart from just peace of mind from bitrot, I use it for the snapshotting capability which makes it super easy to do backups. You can snapshot and send the snapshots to other storage with e.g zfs-autobackup and it's trivial and you can't screw it up. If the snapshots exist on the other drive, you know you have a backup.