If housing prices drop and a crisis ensues, government/central banks lower interest rates and provide stimulus in the form of grants/loans/monetary expansion to prop them up. It becomes clear that the only way to make housing affordable is for authorities to have the political courage to let a crash happen.
Its just that never before has there been an investment firm large enough to take a big enough share of the largest market in the world, the US housing market.
The moment the federal government (Federal Reserve), private equity and investment firms like BlackRock started buying up every available home not nailed down it was the beginning of the end for the US consumer.