I must say that as far as I'm concerned, Nix is very much emblematic of simpler technology. Nix tries to solve problems (such as build impurities) very much by trying to fix things at the source (and contributing back to upstream!), rather than slapping things that work on top of each other, mindlessly using magic like containers. That's one of the reasons why I adore nixpkgs, that they have heroically attempted to fix problems in packages at their sources, and have very much succeeded.