I would guess that most of the sustained price of houses just comes from people trading their existing house which also tripled in value for another one, above a certain cost in markets with very little comparable income earners willing to spend on it.

The house I live in the basement of is valued at $2m, but was $700k a few years ago. Everything in my neighborhood is around the same, and it's otherwise a neighborhood of not super rich people. Who's buying them? It's either going to be newly extremely wealthy people or people who just sold their $2m house.

Nobody's been left holding the bag yet.