In my experience, Nix is very high leverage. My company has ~5 nix gurus, but Nix is invisibly used by hundreds of engineers. Most engineers know we use Nix and that's about it.
Similar experience for me. In my company adopting nix paid off in weeks with no prior experience. Very happy with it almost 10 years later and at much larger scale. The difference between things working reliability or not is too big to overstate.