I tried NixOS, and it seems like it would be easier to maintain than Arch-based systems once you get used to it.
If a problem occurs, canceling the execution of configuration.nix solves everything.
I'm a little scared(?) to install it in a real environment, so I tried installing it in a KVM/QEMU environment first.
I chose KDE at first, but unfortunately, clipboard sharing didn't work, so I reinstalled GNOME.
There weren't any other problems, as far as I can tell.
This is a screenshot of the environment I created by looking at the configuration.nix file with Jemina.