Nix is not competition. Nix is not attracting thousands and thousands of new, young Linux users and potential future contributors like Arch+Hyprland are.
Nix seems really cool, and I'd like to explore it. I'm spending more time with OpenBSD right now as that approach just seems simpler. I use Artix and hyprland at home though. It's a better desktop experience, I think. The only reason I'd use OpenBSD or NixOS in the desktop would be to try and learn it more so I was more comfortable in deployment.