I have trouble distinguishing this post from those on r/wallstreetbets. To be honest, I have seen quite a few posts on wsb that are much more informative than this
The author is George Hotz, who most famously developed some iOS and PS3 exploits and got sued by Sony. I have litle interest in the content of this particular article and I think your evaluation of the article is fair.
It's not interesting though. He was sent an MI300X, released in 2023, to develop his AI stack with.
The MI300X was lacking in a few areas vs the H100 at the time, overall perf and power efficiency were two big areas. Power efficiency is critical atm, that's seriously the biggest barrier to scaling datacenter rollout right now.
AMDs next card might be better on this front, it might not. But this article doesn't talk to anything about the next card. It's referring to a card from 2023.