Oh, I see what you're saying. I personally wouldn't use it to do a 100% filesystem restore. For the sake of simplicity, I'd just use dd/ddrescue to make a .img file and then load that .img file directly into a partition to boot from a new piece of hardware. Likewise if I were doing a big system change like GNOME to KDE or vice versa, I'd just make an .img file before and restore from it if it went wrong.

I think of restic system backups covering something like losing a customized /etc file in an apt upgrade and wanting to get it back.