Such files are relatively easy to create and read, as they are basically shell scripts.

I agree. I lean towards writing in Bash script instead of learning yet another special-purpose language. Nonetheless, the RPM spec doesn’t seem to pose any additional difficulty.

The immutability and configuration of Nix seems so appealing but at this point I’m really comfortable with Arch and it does everything I need in a pretty sane way so idk if I’d switch anytime soon.

Back in 2018, I had the experience of using NixOS. At that time, I noticed that the Nix language had a striking resemblance to Haskell, which stirred up feelings of anxiety within me.

One is that it’s a shell script,

Using Bash sounds convincing to me.

Do you also dislike openSUSE and openMandriva?