housing affordability crises around IT hubs? (sure, the ultimate cause is fear of density, but the proximate cause was a lot of income concentrating in so relatively few people's hands in relatively small areas.)

notice that the real problem is the supply-demand inequality, not that real wages went up for a sector. (and to have a crisis it's almost always necessary for some other conditions to be present to make this one particular imbalance a very significant one that then drives other markets, eg. in case of housing that condition is the artificially very limited supply.)

the COVID stimulus checks were big, but not that big individually compared to the US economy, sectors, regions. people who needed it spent it, who did not put it into meme stocks, or bought something, inflating the price of luxury stuff like high end GPUs. that's most of it. (around 2020 July)

what put the whole economy into a freefall was ~1M excess dead and the rising energy prices giving a big speedup to the already falling supply-side dominos.

Revenues from products with near zero marginal cost.