That's the whole point of snowflake OS. You obviously didn't spend any time looking into the project. The idea is to have GUIs that configure the OS like any other distro, and write and build the Nix configs behind the scenes.
If you want to go beyond writing a configuration.nix then you don't want a beginner friendly anything. Configuration.nix does at least as much as any user-friendly operating system does.
Quite a lot of the beginner-unfriendliness of NixOS is from the need to write your own packages. It's got the biggest repo out of all distros, but it's still pretty easy to need software that isn't in nixpkgs. Even easier if you're developing software, since then you need a Nix derivation to have a development environment which can build your software.
A good editor and an LLM could maybe do something sort of useful for helping people customize packages. Used sparingly alongside programmatic generation of Nix code and old-fashioned templating, maybe it could even be reliable enough to be a win
