I can't speak for macOS, but on Linux using Nix as package manager is relatively painless once you follow a recipe such as this one:

https://www.tecmint.com/nix-package-manager-for-linux/

There may be bugs with packages though, so I use it for what works for me. Not when it breaks with local dynamic libraries. It's a nice addition to get more recent packages than the distro offers.

Guix can be used as additional package manager as well.

NixOS (the distro) is steep though, like driving madly along a cliff steep. Guix even more so but with less speed.