re: For the first time in our nation's history, a 30-year-old isn't doing as well their parent

That difference in income might be connected to a difference in knowledge. Young adults today may or may not be dumber but they are definitely more poorly educated. I've played golf with 30 y.o. college graduates who couldn't add a few single digit numbers in their head. They had to use a calculator after the round to get their score.