I've heard this theme for years on this forum. I can appreciate the logic of frugality after a massive party hangover (GFC) but obviously the Central bankers were forced into debt on debt. A decade of growth and only recently more expensive capital which Powell is now trying to play down the unaffordable theme by saying US is in a good position (sustainability is what I read).
I have no idea based on the bank reserve that Feds are propping up with QE found its way to the higher yielding stock markets and EM but we can see a decade of SP500/DJ30 continuing the bull trend is not a spike! Your observation that AUD has very little USD denominated debts with the currency sell off is something I never thought about unlike the Indian Rupees, Turkish Lira and a host of other EM currencies facing another cheap funding debt parties in hangover due to US monetary and probably trade wars cranking up the rhetoric/actions.