I'm no AI booster by any stretch of the imagination, but it's not "run[ning] ... computer systems" in this case. Your NixOS setup is defined by declarative config files, and nix builds or updates a working system from them. AI in this case is just writing the config files, which you'd then (hopefully) read and at least vaguely understand before applying them.

It generates a config file. You can read it before applying it. While Nix may be nigh intractable to write for some people, it is quite a bit easier to read, and any shenanigans would immediately be noticed.

that's quite interesting because I would love for AI to run my systems, given it is capable enough (and it is given right tools). Jarvis anyone?

It writes into a configuration file that I git diff before applying.