The critical thing that changed in the 1970s is that USD stopped being convertible against gold. So now the USD is the default reserve of value for countries/central banks worldwide. Therefore the US has the exorbitant privilege of printing as many greenbacks as you like, restricted only by inflation (and when has inflation been a problem in the last few decades?).

Other countries run into hard foreign accounts restrictions when loosening monetary policy too much (the LOCALMONEY/USD rate shoots up, and with it commodity prices, oil etc.) Bernanke-type QE is something out of Derrida or Baudrillard. Conservative economists have railed against QE thinking of old-school macroeconomics models that only hold for other countries.

I guess there's social and political dysfunction to come from this lack of restrictions. It mirrors the folk sociology of "boomers" e.g. https://www.youtube.com/watch?v=mBNKUda-s6M