... illegal aliens ... Wall Street owned short-term and long-term rentals ... NIMBY zoning laws ... available land being banked by communities as "conservation land" ... short answer, the problem is Government
If there is a buck to be made, developers will build it ... until Government gets in the way.
Many communities do not want to grow, but, they do want new $100 million middle school buildings.
Government funds should be directed to YIMBY communities, and let NIMBY communities starve for funding, public transportation stations, etc.