That's fair. I blamed immutability when I should have blamed the implementation. Thanks for helping me realize my mistake. :)
Availability of packages is what makes or breaks a distribution, though. If I can't (easily) install the software I need to do my job, I choose a distribution that can. My home Ubuntu server isn't bringing me joy, so maybe now's a good time to give Nix another shot.
In my experience the Nvidia driver support has been pretty painless (once you figure out the correct settings in configuration.nix of course), and the availability of packages is by far the best of any linux distro I've used.
I've been working on a project that uses Nix, and from an archlinux host with Nvidia hardware it has been very far from painless, with nixGL breaking every time Arch updates glibc
I think if you don't use some relatively niche packages, nix is fine. However there are some quirks such as setting LD_LIBRARY_PATH for CUDA that may need some tinkering.
If you want to give nix another try, I strongly recommend you to use nix flakes and home manager. Nix flakes allows you to pin dependency versions, and home manager provides a lot of configurations for commonly used packages.
Availability of packages is what makes or breaks a distribution, though. If I can't (easily) install the software I need to do my job, I choose a distribution that can. My home Ubuntu server isn't bringing me joy, so maybe now's a good time to give Nix another shot.
Fingers crossed for Nvidia driver support...