The conversion of US society from an agricultural one to an industrial one to an information/services one probably the larger trend driving results here, especially if the quality of produce/soil is something you're thinking about. The role fiat currency played in that is debatable I'll grant.

RE: terrible art, the rise of that is the rise of art for lower classes in terms of more of it being produced and seen, which is a good thing I'd argue, as well as comparing art made in a 10 year period say with all of the best art western civilization has produced in the past 500 years.