[AnthonyMouse]

> It allowed middle earners to escape the urban "law of rent."

Suburbs not only aren't required for this, requiring them to be suburbs actually makes it worse.

Suppose you have 1000 parcels of land and you need 3000 housing units. Obviously you need an average of three units per parcel. If 950 of the parcels are zoned to allow only one unit, the remaining 50 parcels then need to have an average of 41 units each.

Those parcels then become dramatically more expensive because they're the only place additional units can be added. Rents then have to rise to reflect the higher costs. Worse, some of those parcels already have e.g. 30 units but the cost of demolishing a perfectly good 30-unit building to build a slightly larger one is prohibitive, so now there is a shortfall and even the one-unit-per-parcel land ends up with higher rents.