If you don't want to fully commit to the OS or the Package Manager, you can use Nixpkgs alongside your OS and other package managers by installing Nixpkgs on your Mac or Linux OS.

For the functional language and UX, I agree there's room for improvement. If you don't want to dive into learning Nix, you could use a wrapper that simplifies the UX for creating projects. We built one called Devbox (https://jetpack.io/devbox), which uses JSON for it's config format and has a CLI inspired by more familiar tools like Yarn.