Regarding "not supposed to do that": the docs mention you can install packages with commands like "nix-env -iA <package name>", using nix approximately the same way as apt or pacman. -- Trouble is, this is kindof a footgun. (e.g. it's a bad idea to run this command with sudo, even though you'd use sudo for equivalent commands). So, it's easier to just say "you're not supposed to do that".

Right . But it's a bunch of this. Another example is flakes. It was behind an experimental flag and was apparently what everybody was using already. There was only 3rd party documentation if I remember correctly. Twice I tried to use Nix and twice it kicked my ass. I never had this experience with any other unixy end-user software.