RE: Ransomware the end of the 3-2-1 backup?

I highly recommend TrueNAS as a network file server which uses ZFS. This supports any operating system as your desktop. Rsync.net also has a remote ZFS for off-site where you can send backups to the cloud with immutable snapshots.

The easiest, is just using a couple of USB HDD and never have them all connected to your machine at the same time. I wouldn't recommend running any one drive for longer than 7 days, although daily switching would be ideal it is time consuming.