The only way to lower the cost of housing, is to enact policies that force current homeowners, and basically everyone else in the current housing supply chain, to lose enormous amounts of money. Everyone from material suppliers to construction workers would go out of business, and everyone holding mortgages would immediately find themselves drowning in debt they will never be able to repay.

This would be political suicide for anyone willing to enact these policies. Imagine being the one who effectively tanked an entire industry, just to hit the "reset" switch on prices?