Building more doesn't devalue their land. It actually increases the value simply due to the fact that there's more revenue to be made on the same amount of land

Building more doesn't devalue their land. It actually increases the value simply due to the fact that there's more revenue to be made on the same amount of land. It also doesn't solve the housing crunch, because there's no meeting the demand. It doesn't matter how dense you go; even Manhattan isn't dense enough. There are two things this does accomplish, though: - It exacerbates the wealth divide, as it increases the market entrance costs and moves ownership into the hands of fewer and fewer "landed gentry" who, invariably, build rental units. - It destroys quality of life for existing residents, as it foists all the scaling issues of upzoned density (traffic, crime, costs, required size of bureaucracy) right onto them.