MarioC can Restic be actually used to make system snapshots the same way as Timeshift?
No, it works a little differently. Restic takes advantage of the fact that Solus editions only take a few minutes to install. And in the script that I provided, the first part of doing a backup is to create a list of all the packages that have been installed that are not part of the initial installation. That list, called InstalledPackages, is saved to your /home directory, where all the rest of your things are (or should be).
So the process of doing a restore is like this:
(1) Install the edition of Solus that you choose to use. And install restic.
(2) Do an eopkg update.
(3) Restore the backup you want with Restic. This will also restore the InstalledPackages list of added software.
(4) Use the Restic Restore command (eopkg it InstalledPackages) that will restore all those packages.
This all actually doesn't take much time at all. And by starting with a new OS installation, you have the option to change things that you've thought of after the initial installation. You might want to increase the size of your swap partition, for example, so you can hibernate your computer when you're not using it. (That's a very good idea.) You might even want to install a different edition of Solus the next time.
The end result is that you get a clean OS, freshly updated, and your /home directory is restored, along with all the packages that were installed since your initial OS installation. That is, your computer will be exactly where it was when you made the backup. (You might need to change some settings again, but that's pretty trivial.)