I’m probably the overkill case because I have AD+vC and a ton of VMs.
RPO 24H for main desktop and critical VMs like vCenter, domain controllers, DHCP, DNS, Unifi controller, etc.
Twice a week for laptops and remote desktop target VMs
Once a week for everything else.
Backups are kept: (may be plus or minus a bit)
Daily backups for a week
Weekly backups for a month
Monthly backups for a year
Yearly backups for 2-3y
The software I have (Synology Active Backup) captures data using incremental backups where possible, but if it loses its incremental marker (system restore in windows, change-block tracking in VMware, rsync for file servers), it will generate a full backup and deduplicate (iirc).
From the many times this has saved me from various bad things happening for various reasons, I want to say the RTO is about 2-6h for a VM to restore and 18 for a desktop to restore from the point at which I decide to go back to a backup.
Right now my main limitation is my poor quad core Synology is running a little hot on the CPU front, so some of those have farther apart RPOs than I’d like.