Just want to mention, that snapper is doing this
Yep. But snapper only does snapshots and as such only prevents from logical failures (like accidentally deleting/overwriting data or when used on the rootfs after failing software upgrades allowing to revert to last known working state -- this was the problem @dkxls ran into years ago on OpenSuse and the challenges are outlined here).
If you want to use snapshots also for 'real' backup protecting from physical failures then with those modern filesystems other tools like btrbk or znapzend are way more interesting since those do all the necessary snapshot handling embedded in an automated way to transfer data to another disk or even better another location (e.g. a different SBC in another room, building or town).
Physical separation of the backups is crucial, see lesson 3 here: http://www.taobackup.com/