There are plenty of third-party package managers for macOS that work fine. I would prefer it if Apple picked one to officially support, but installing Homebrew takes me ten minutes and then I never have to think about it again.
I’ve always wanted to use Nix and have tried to get started a few times. It has always ended up seeming more trouble than it’s worth.
* Nix doesn't have support for GUI apps like homebrew cask does - which meant I couldn't drop homebrew anyway. * The nix ecosystem forums suggest using nix-shell for managing packages for other languages, eg. python, java - but it's been really difficult to convince team members to use nix instead of pyenv, conda, gradle etc