Correction through time rather than price could be one way this path doesn't get taken. That is, we get more kangaroo as people get shaken out of the market or take their positions and leave.
The retirement of the baby boomers is one substantial difference now than DotCom and GFC. Lots of people at retirement now got their come-to-Jesus moment when the stock market crashed then. None of them want to relive that experience. That capital is gradually getting taken out of the market now as people make their periodic withdrawals. The average year a baby boomer retired was last year.