Does it? I'm pretty sure you're able to run Nix (the package manager) on Arch Linux for example, I'm also pretty sure you can do that on things like macOS too but that I haven't tested myself.
Or maybe something regarding this has changed recently?
edit: I actually never checked, but I guess nothing stops home-manager or nix-darwin from working too, but I don't think either supports running containers by default. EOD all NixOS does is make a systemd service which runs `docker run ..` for you.