Nix needs a typed language, better CLI interface, better documentation, a distributed cache, to to get rid of the monorepo / single source of control, to support different builders (aka not just bash), and have a less toxic community.
For nix to be used by normal, non technical users, it must have a GUI. That is not optional.
Nix could be great for a lot of things, but it's not the only solution and won't be the last.