A housing bust in 2008 washed a lot of capital and talent out of the house construction industry, and the current boom is hard to supply with construction capacity even when there is land to build on. And also, even if the land exists, there is already a SFH on it that needs to be torn down, so we are densifying at a slower rate than we need to. Couple that with an even increasing focus of good job opportunities into a few hot metros, the whole US housing market becomes one hot mess.