This seems absurdly naive to me with the path big tech has taken in the last 5 years. There’s literally infinite upside and almost no downside to constraining the ecosystem for the big players.

You don’t think that eventually Google/OpenAI are going to go to the government and say, “it’s really dangerous to have all these foreign/unreglated models being used everywhere could you please get rid of them?”. Suddenly they have an oligopoly on the market.

right, and the less we rely on ChatGPT and Claude, the more we give power to "all other frontier models", which right now have very, very little market share

the companies could merge or buy each other

Yes they are.

It'll all be open weights commodity just like all Unix vendors disappeared