I don't see the serious answer in your thread: Because the job of a package manager is complex and humanity hasn't figured out a universally satisfactory solut

I don't see the serious answer in your thread: Because the job of a package manager is complex and humanity hasn't figured out a universally satisfactory solution. Research and development are ongoing, and the state of the art is at a level of complexity that I'd compare to a doctoral project or something, requiring one to throw away tons of the abstractions they know and learn a lot from scratch (nix).