It is not just about deploying, which to be honest is great. I can build software for my Raspberry Potato on my desktop and remote deploy the config using one line in the terminal.

It is also for when I decide to tinker with my system by changing stuff like audio latency and clock rates for real time audio, USB HID overrides and so on. Normally I would be scared to break something, or worse, fix something without knowing what did it and thus learning nothing from my efforts.

The best part is having a system that you can approach almost scientifically, making it unbreakable in the sense that you can immediately revert to a true former state, both as a build and a config using GRUB and Git, respectively.

But NixOS is so cool though. I use NixOS btw