I do restore my VMs to deplicate VMs to test from time to time (it's pretty easy with Proxmox) but I use Restic for data backups which encrypts the data before uploading it, so one should restore a backup to a different folder to ensure the data integrity and that you didn't forget your keys ahah
You don't have to do it every week or month, but it's worth doing it a few times a year or when you change something!