True. That shift would be in the last couple of years. Maybe Vietnam is next China. But this is still an emerging event. What China did to the US already happened.

Vietnam doesn't have the population to be the next China. I wish them the best, but their time will not last nearly as long as China. (or more likely it lasts as long but it is shared with a bunch of other countries in Asia, Africa, and/or South America)

Nowadays, with so much automation going around, Vietnam can afford to become the next China even without a comparable population. Not that I think it will, but see the story of the Four Asian Tigers to realize how smaller countries can suddenly have a much bigger importance to the world economy.

Made Americans a lot richer and allowed them to consume more?

Made the Chinese even more richer and technologically superior to the us in many many areas as well.

Yes, it's a win-win situation.