The problem is that US zoning and finance has basically killed off the small upstart developer; think of the general concept of a house flipper, but instead of remodeling the interior they replace one home with two or three smaller homes on the same lot.

This still happens on a smaller scale in older urban areas, simply because price per square foot in places like New York make it hard to assemble a full city block unless you have half a billion on hand, and even if you did land parcels don't become available all at once like that.

This type of "missing middle" development still happens where I currently live in Seattle to a limited extent, but I would really like to see regulations limiting horizontal massing of individual buildings to prevent this problem.