Earlier quoted context omitted.
> Housing crisis is only about the very few already overpopulated spots being hyper-attractive for people to move in because that's where opportunities are. Why not build hyper-dense housing? If you have functional public spaces you don't need as much private space. We used to have boarding houses etc. I don't need my own bathroom, I need a bathroom. I rarely use my kitchen, I just need access to one.
How about commuting? Pollution? School, hospital and other public services capacity? Crime arising from simply the rich place being affordable, inviting undesirables?
Giving the "undesirables" a decent place and means to live reduces crime.