> USA keeps getting a larger GDP you say, yet the population at large seems to be getting poorer

People in the US may be many things but poor is not one of them. The median household income is ~$85k and the median household lives somewhere pretty inexpensive. The amount of money Americans can afford to waste on things they don't need is unmatched.

"Poor" isn't just "doesn't have N USD", purchasing power as just one example, matters so much more. But maybe it was a poor choice of words on my part, sorry.