Why are we assuming "developers are never going to build housing that lowers the price of housing overall"? This seems to run contrary to research on the issue.

Why are we assuming "developers are never going to build housing that lowers the price of housing overall"? This seems to run contrary to research on the issue. See: https://www.upjohn.org/research-highlights/new-construction-makes-homes-more-affordable-even-those-who-cant-afford-new-units https://www.upjohn.org/research-highlights/new-construction-...