There are efforts in this direction already if you want to contribute: SnowflakeOS - Creating a GUI focused NixOS-based distro
Yep, you highlight parts of that effort, and they’re far from ready. I think the community as a whole is split between not caring much about these things for lack of personal use cases and being excited about it but not having time/enough interest to make time (for lack of personal use cases).
NixOS also certainly has a way to go for adoption among more advanced users. I mean, you already started off talking about how cool you think a certain footgun is: stop-using-nix-env.privatevoid.net/
As a whole, I think it may be difficult to get a “user friendly” NixOS that is distinct enough to the kind of user who would need it to actually stand out against ubuntu/debian/fedora. Most such users probably care little about whether their configuration is declarative or imperative, it’ll effectively be the same without maintenance. But it is a cool thought, it’d be awesome to help debug things for friends and people on random forums if I could see their mess directly 