> Shouldn’t we fear they start doing only close source like most us labs once they catch up in market shares ?

IMHO no.

I think it is relatively safe to say that the predominant reason the US labs are closed source is so they can hype up their trillion-dollar valuations on pretty much negative return on capital employed, all propped up by fragile circular financing.

Never say never, of course. But I just don't see it happening any time soon.

Closing future models won't take away our access to the open weight ones.

Yeah, but that mousetrap keeps working for SV startups, what makes you think it won't work for Chinese ones?

Uber spent a decade undermining taxis, and once it had market share, it stopped giving away rides and raised prices. It now costs more than a regular taxi, with the quality of the ride being... At best proportionate to the premium in price.