Zoning which prohibits or heavily restricts multi-unit housing in cities, and material shortages and high prices for steel and lumber which impacts new single family homes.
The issue is cheap credit and the lack of an LVT that would avoid all the economical and ethical issues with land ownership.
I don't think it's a panacea at all, I just think it would be the most effect with the smallest disruption (in that it's simply a reform to be done inside the framework of free market, private property, etc).