My cloud backup method is running Restic inside any VMs or Containers with important data (I use Backrest to manage it easily).
The reason is I don't want to be backing up caches, logs, and other junk that isn't important to cloud storage, since it's just wasted storage space and bandwidth.
Yeah, I have local proxmox backups to an external HDD for stuff like "oops I broke it" or a drive failure, but the online backups are for something catastrophic like the house burned down with the server in it, so I'm not particularly worried about them being more work to restore.