Most VMs backed up daily, depending on how vital then stored for anything from 3 days - 30 days. Few machines are backed up 3 times a week cause they’re tests servers and we’ll take snapshots as and when they’re getting actively used. Finally a couple of machines are backed up 6 hourly for data relevancy.
Everything replicated to a second backup server off-site and have a hardened repo for immutable backups.