You cannot compare NixOS to ubuntu… even for as a new user to more adept user comparison, NixOS is really complicated. I’m not saying it’s bad, just that the documentation on how it works could be better. I’ve tried to use NixOS and nix itself multiple times and they were a nightmare to setup each time, especially NixOS (nix itself isn’t as complicated to me but it has some annoying things with proprietary software and not integrating with desktops at all without using hacky scripts).