I'm not going to force anyone to debate with me, but if your economic theory says that Amazon's prices should have dropped this year, and they didn't, then your economic theory is wrong and/or incomplete. That seems like a pretty straightforward test.
Sometimes companies make more money and they don't lower prices, pass those increases onto workers, or expand. This is something that is observable just by looking at price/wage trends in different industries/companies and comparing them with the associated profit increases.
We know that "profits go up, prices go down" is too simplistic and/or flawed of a model to talk about the real world because it's not accurately predicting what companies do in the real world.