There's a lot more going on with restic aside from just that, but yes. So with an rsync of your home dir (for example), it's reliant on the FS to do compression and deduplication (ZFS,btrs), and/or it will still take up a lot of wasted space. Say you got ransom-wared. It's okay you have that rsync backup, but oh crap it got ransom-wared to. No more backups to try? Restic gives you snapshots for whatever increment you set and just handles it simply. You can then restore one file from any of the snaphots (history) or every single file. Restoreing 250kb vs 400TB is quite a difference. The benefits of this, are huge even beyond the fire and forget capability.

I mean, rsync handling everything via mirroring and pushed to a ZFS FS, would be sort of the same thing.