Come on now. That's a super clickbait title. The article actually says the race is at a dead heat and LLM training for the same competency is getting cheaper, not that it's "over".
In what world do you live in where races end just because the score is tied?
I feel it doesn't really matter which country or company has which model open at the moment. Whichever company, open source-based or closed that hits AGI or something much closer to it first wins, period. We're not there yet, we've got lovely conversationalists summarizing all our web crawled answers back to us. It doesn't seem like throwing chips and compute at the problem is the answer, and stifling competition via hardware is just bailing water. I do think he's at least kinda right that it's going to take another paradigm shift in LLMs, traders and other models to some other idea that eventually does it. I don't expect it out of GPT-5.
Odd, that's exactly what I interpreted the title to mean. "Supremacy" means one side has a total and insurmountable lead and control. That's how lots of China hawks in the West talk about it, arguing that they must do everything to stop China from building their own ChatGPT. The article is a pretty good summary of why no one side will achieve supremacy. And if you have been following Gary Marcus, he's been arguing this for a while now.