I’ve tried Nix on a Mac half a dozen times. It always ends with frustration.
Homebrew works amazingly if you actually want to be on a Mac. If you HATE everything about MacOS and Apple and someone forced you to use a Mac, then use Docker and Nix inside of that.
Nix should never be used on a Mac. It is a philosophical disaster. Don’t do it. Delete the repos and the world will be better off.