[beerandt]

The key to understanding all of this is that a huge set of Americans 'want' to pay more as an exclusionary benefit.

With section 8 (fed housing welfare) rules, any multifamily structure has a better than not chance of becoming slum housing in a time frame less than the average span of homeownership.

Which is both about property values and not wanting to live in/near section 8 residents.

"Planning" and zoning aren't the problem, they're the enforcement mechanism. (Since police and other public enforcement of quality of life issues has been all but neutered in the name of equity/civil-rights/whatever.)

Same reason for the seemingly inexplicable popularity of HOAs that everyone seems to hate.

High prices are one of many resultant 'enforcement' prongs.