It DID crash the economy, but then the federal government stepped in, implemented the "too big to fail" doctrine, and blunted the damage into a recession instead of a depression. In that process, though, they exposed their weakness: the government will step in to rescue companies on which the US economy most relies.
This is particularly relevant when, amidst a widely acknowledged AI investment bubble, Google CEO Sundar Pichai says in the same breath that AI investment is at least partially irrational and regarding a bursting bubble "I think no company is going to be immune." That's not a warning... that's a threat and a dogwhistle to the government effectively saying, "If you allow this bubble to burst, everyone will suffer".
This is that "moral hazard" about which economists and political scientists warned during the mortgage crisis. (https://en.wikipedia.org/wiki/Moral_hazard) They know that they won't bear the harm of the risks they've taken.