That's not how it works. The developers build luxury apartments, and the wealthy people who are living it shitty, 100+ year old buildings (most of Lower Manhatt

That's not how it works. The developers build luxury apartments, and the wealthy people who are living it shitty, 100+ year old buildings (most of Lower Manhattan, for example) move into those buildings. The old, shitty apartments then become less expensive and lower-income people are able to live there.