You're not describing a zero sum interaction because the gain in China has almost certainly outstripped the loss in the US. That's pretty much the story of globalization so far.
This is precisely the academic theory bubble talk I was referring to.
On balance no one cares that some Chinese peasants had a huge increase in quality of life. Their lives, and the lives of their children were significantly degraded so some executives and owners could get obscenely rich. If you zoom out far enough literally nothing is zero sum given the conservation of energy. But that’s a silly argument.
That it may someday be a net win for humanity (and this is entirely uncertain) is very much immaterial to anyone other than folks so disconnected from reality that they are insulated from the impact these theoretical games have on real people in their own country and communities.
Of course, it's a net loss for the rust belt.