@mcc Well, it certainly can't help with the things that happen outside its POV. Like, if you use it as a second package manager on top of a non-NixOS Linux, they will be separate things. You can do that though, if it helps with managing your dev stuff for example.
Or, language-specific package managers, again they can do their own thing, where maybe you just used Nix to get the rest of the environment configured.
@tim_lavoie sounds like what you're saying is nixos solves the problem and nix doesn't