That is because of China and US positions in the global system over this time. The wage/labor/inequality story is broadly true across the global north; China can credit forward thinking central planning, social programs, and industrialization for its economic progress (yet it continues to live under authoritarian rule).
I guess if you have the opportunity to have your stuff made by cheap or free labour whether low paid Chinese or AI robots, societies have a choice how to distribute the benefits which has varied from everything to the rich in the US to fairly even in France say. Such choices will be important with AI.
