I was mostly joking, of course. I appreciate the use case. It's just that 99% of people are spinning new machines once every decade. Having a reproducible setup is something of interest for a very narrow band of system managers.
I truly believe that for those who are spinning new hardware every day and need an ideal setup every time, a system image is far more practical. With much more robust tooling available. I've read other replies and for them all, I notice that using Universal Blue to package and deploy a system image would take a tiny fraction of the time it takes just learning Nix basic syntax. It's so niche it seems almost not worth any of the effort to learn.