> I mean, nothing stops you from building your image of KDE Linux (or any immutable distro) with a built-in restic config.

I hear you. The problem is, that basically nothing stops you from building anything yourself. The difference is, that there is no easy-to-use build-in solution (like time machine) and ease of use is what makes the difference. Especially a TIME difference. Of course there is software SIMILAR to time machine, but it seems to be hard to write something rock solid and easy-to-use.

In fact I also have built it myself: https://github.com/sandreas/zarch A script that installs Arch on ZFS with ZFSBootMenu and preconfigurable "profiles" which packages and aurs to use. Support for CachyOS Kernel with integrated ZFS is on my list.

I already thought putting together a Raspberry PI Image that uses SSH to PULL backups over the network from preconfigured hosts with preconfigured root public keys and is easily configurable via terminalUI, but I did not find the time yet :-) Maybe syncthing just is enough...