It is a win-win even when one side wins more than the other.
Also you are operating in dollars space instead of utility space, which is a mistake. Even if a poor person "only" gains an extra $2000/year in annual earnings due to globalization, that can be a life changing amount of additional wealth given that their utility function is highly sensitive to small changes.
It didn't. Yes, the gap certainly has widened with countries that didn't partake in globalisation. Here I'm thinking countries in Africa, North Korea and Afghanistan.
But if you look at poorer countries that did invite the richer ones so that could provide labour at a lower cost, countries like Vietnam, Thailand, South Korea, and yes China - the gap has gone from peasant farmers who starved in lean years to industrial nations that are starting to rival the incumbents. Places like Singapore and Japan are in fact now wealthier than most of the incumbents.
It's not a win-win when the rich side wins 100 and the poor side 10