The answer is that people benefit from stability, both financially and socially.

Single and duplex zoning was a great deal for cities and close suburbs because they are operationally efficient - less services are required; fewer parks, fewer schools, fewer calls for fire and police service. It’s a good deal for people because financially it has been historically better to own a building and land vs rent or buy into coops.

For existing, pre-1990 low density urban neighborhoods, retrofitting medium density housing is usually a shitshow. Why?

- The areas of were detached houses that usually have yards, no parks, fire stations, etc.

- Because of healthcare and tax policy, it’s very difficult to run the types of small businesses that are needed to support an urban lifestyle. Boutiques, restaurants/bars and similar

- Because there are no local amenities, people still need cars, and there’s rarely enough parking to meet demand.

- Schools are tied to geography, and changes in school assignments are impactful and traumatic to families.

- Developers usually get tax credits for including street level retail, but have no financial incentive to rent them as tax policy pays them to do nothing.

If you look at functioning urban environments like NYC, you see it all over the place. I grew up in Brooklyn and Queens. As small retail fades away, major big box scaled retail moves in. The neighborhood 20-40k sq ft grocery stores of my childhood (Key Food, Finest, A&P, ShopRite) are being displaced by bodegas at the low end and big developments on the high end - which drive demand for cars and exclude people relying on transit.

You can only fix this stuff with fairly radical change, that will be very painful for lots of stakeholders.