[throwaway81523]

Disclosure: I've never done it. But I looked at some CUDA code from Leela Chess Zero and it made reasonable sense. It's just C++ with some slight changes. The GPU architecture is a little bit quirky but not that complicated either. Plus there are libraries like pytorch that handle most of the GPU stuff for you.

I would say ML concepts and algorithms are way more complicated than GPU programming per se. The fast.ai lectures were pretty understandable when I watched some of them a few years ago, but attention wasn't yet invented, and it was pretty obvious that it would take a fair amount of trial and error to become skilful at writing simple recognizers.