Earlier quoted context omitted.
I don't think the people who moved to the housing projects were typically sleeping on the streets. I think it was more a case of upgrading to modern sanitation standards etc. That said, I have no real detailed knowledge, and would be happy to learn how wrong I am about this :)
Bottom living standards were a lot lower back then: people could live in shacks without plumbing, flop houses were plentiful. These days none of that is legally allowed, so people would have fallen into that housing 50-80 years ago are homeless today. That being said, poverty reductions between then and now are real, it’s only that our standards keep getting higher (as they should).
The insanity of "we can't let you have a bad X, so you get no X!" is one of my least favorite things in this era...