I wonder why Chinese AI labs are losers?

In the short term maybe yes, in the long term, maybe they are the winners, they can build on top of cheap inference stack and eventually win on pricing

Because having unrestricted access to both American and Chinese hardware is better than only Chinese hardware. Long term or short term. More suppliers the better.

Perhaps the future Chinese hardware would not be so cheap or performant had Nvidia export controls not been put into place.

Logically one would expect it to be relatively more expensive and less performant because it does not have to compete with Nvidia’s hardware.

I'm not sure I agree. The market pressure for this innovation might not have been there with Nvidia chips still available. In this case it is coming from necessity.