What aspect of urban development caused these people to be homeless, drug-addicted, or criminal? Did the frequency of bus service get them addicted to drugs? Did the taller building height take their job?
We make this unconscious logical leap that there's some justification for human misery to be concentrated in urban cores. I live in a dense urban core right now, and I see human misery when I go outside. I think "boy, it'd be nice to move to an area where this miserable person isn't". But... it'd be ridiculous to be happy by pretending misery doesn't exist because it's not in eyeshot. If that were the case, we should just ship miserable people to the suburbs where I don't have to see them (that would be cheaper and more convenient for me!). The wealth density of an urban neighborhood is huge, there's easily enough money to relocate miserable people into even rich suburbs.
The better thing to do is to make choices that cause there to be fewer miserable people. I'm optimistic that the current debate around the urban-suburban-rural divide and the role of cars will make us recognize that there's huge mutual interest in the idea that _public spaces should be nice_, and that seeing the misery that results from our policy choices is a feature and not a bug.
These also are the highest cost of living places in the world to live. It's not practical to think everyone could live like that. They also are miserable with homeless people, drug addicts, and crime. It also relies on a huge network of people commuting to those jobs to support that area.
You can't have 30 restaurants within a few square miles with all the people to support that living there in homes. You'd need a combination of super dense housing and people commuting. It's really inefficient.