You clearly live in a fantasy world.
Certainly there are families in those areas living on much less, but they generally live in extremely cramped quarters in dangerous neighborhoods (with rent controlled apartments subsidized by higher income people), send their children to dangerous public schools where little real education goes on, and can only dream of such luxuries as owning (or even renting) a few square feet of land where they could plant a few flowers. To take an example of a working class couple I know who lived in Brooklyn (cheaper than Manhattan): about 10 years ago (so factor inflation into this) I happened to know what both of them earned, he's a trash collector and then made about $60K, she's a secretary and then made about 75K. They live in a rented 2-bedroom apartment which is one floor of a 3 floor/3 family house, have one not-too-recent car, and their son attends public school. That's the lifestyle about$160-170K would buy now. No, they're not starving, but they're not living nearly as well as a family of three could live on $40,000 in most parts of the country -- and they're in alternative minimum tax income range.