This will sound rude, but I'm more and more convinced that people immersed in nix have never seen a real person in real life. defined boolean expression reference true. wat. I'm a technical person, and I have no idea what this is. And for technical people? Literally everyone says that "nix is really hard to get started with". nix and nix-related developers, please, please find some real people and talk to them.
You probably don't have a problem that this solves. I.e., some people still download random zipfiles from the internet and install each individual app from a wizard dialog onto their Windows 10 machine. They find software repositories and package managers confusing and overengineered. I guess that's okay.
I use Debian and Redhat happily, also do plenty of Docker. I really want to love Nix and have tried a few times (even submitting some package updates), but just kept bouncing off it and giving up.