NIX IS FOR REPRODUCIBLE BUILDS. That’s fucking it, seriously. It’s literally on their website.
This post is specifically about NixOS and friends, though.
IT’S A HORRIFIC EXPERIENCE FOR NEW USERS TRYING TO RUN A DESKTOP. Steer clear.
There are thousands of users who run NixOS on their desktop, and thousands more users of home-manager (or nix-darwin) on macOS. If you are ready to put in the time and learn how it works, it’s wonderful - your entire distribution, the thing through which you interact with computers, becomes just another project in your ~/projects, rather than something you have to manually configure. You can’t forget “how to configure $X”, because it is all recorded in one place and done automatically when you get a new machine or update or whatever. It’s GNU Stow on steroids, for your entire system.
There are a lot of downsides for sure as well (mostly the learning curve, and having to fix the buggy bullshit in some software which only runs well in FHS), but if you are a software developer (or adjacent) and like Linux, NixOS is still awesome.
I don’t know if it’s of any solace, Linux used to be a much more… ahem… “involved” experience a decade or two ago. This was more-or-less the norm:
I can’t really say what the newcomer experience is nowadays, but I can say for sure that even in the worst-case (as it was in the times when I started using it), after a couple months of furious issue-fixing and trying new things, you will eventually settle on a setup that works for you. Some people actually get addicted to all the problem-solving and start looking for more issues to fix; some start distrohopping to find a “more perfect setup”, getting their fix of issue-fixing in the process. If you’re not one of them, congrats, at that point you can (mostly) just continue using it, until you need to update your hardware, then process may or may not be repeated depending on your luck. If you really hate fixing issues twice, you can look in the direction of declarative distros like NixOS or Guix, but I will warn you that the two-three months of furious hacking is still very much a thing here, but after that you’re set more or less for life.