How would that look with at least 3 US companies, probably 2 Chinese ones and at least 1 European company developing state of the art LLMs?

Network effects usually destroy or marginalized competition until they themselves start stagnating decaying. Sometimes they produce partially-overlapping duopolies, but maintain their monopoly-like power.

Facebook marginalized linkedin and sent twitter into a niche.

Internet Explorer and Windows destroyed competition, for a long while.

Google Search marginalized everyone for over 20 years.

These are multi-trillion-dollar businesses. If OpenAI creates a network effect of some sort they can join the league.

Like a very over-served market, I think. I see perhaps three survivors long term, or at most one gorilla, two chimps, and perhaps a few very small niche-focused monkeys.