> While they might have been paying lower taxes, who says they weren't consuming/spending more?

Economists do measure the "velocity of money". And it really is higher among the poor, for common-sense reasons; someone who's living paycheck to paycheck is (almost by definition) spending all of their income, putting it straight back into circulation, whereas the wealthy are more likely to save some (which yes does recirculate as investment to an extent, but the investor as rentier takes their cut, and investment income is often undertaxed), spend some abroad, or spend in less efficient industries (e.g. high-end handcrafted anything, where you're paying a master craftsman who won't actually spend a lot of their time producing things, and won't be pulling back anywhere near as much through the productive economy (e.g. buying materials) compared to the same amount of money spent on mass-produced goods).