Moreover, it's irrelevant. Demand vastly overshadows supply, hence the insane prices. That's it. There isn't remotely enough of a basic human need. Everything else is window dressing until we address that fundamental, econ. 101 problem.
The mortgage tax deduction is basically dead for most of us since Trump’s tax reform that raised the standard deduction way above what most people would get from tax deductible interest. At least until 2025, unless something changes.