Disagree. The larger selling point is Nix reproducible builds. Getting a reproducible developer environment is a start, but everything inside that “shell” is then mutable. Hiding Nix behind YAML is obscuring a tool, Nix, to make the entire build stateless—and that YAML can often be a stopping point where folks aren’t going ‘deeper’ to unlock the reproducible build part.

There are things it does that are very helpful, like enabling a PostgreSQL server without much setup, but other things like forcing certain language toolsets goes a bit too far—especially when those tools are already in Nixpkgs and setting up a base devShell provisioned with a few console tools is one of the easiest things to do with Nix the language already.