I use btrfs snapshots and btrbk

btrfs is a great filesystem and btrbk complements it easily. Switching between snapshots is also really easy if something goes wrong and you need to restore.

Archwiki docs for btrfs: https://wiki.archlinux.org/title/Btrfs#Incremental_backup_to_external_drive

Of course you'd still want a remote location to backup to. You can use an encrypted volume with cloud storage. So google drive, etc all work.