As someone living in a city gutted by de-industrialization and the drug trade (Wilmington, DE), I think it's news that 40 years later, these places are still in poor shape. The usual response to concerns about technology or globalization putting people out of work is that it just frees them up to work on something better and more useful. "New jobs will replace those that are lost." Well, the people here are still waiting for those new jobs to replace the ones that got automated or outsourced away.
> And Camden is a thousand miles from here, but where I live you need a car and a suburban house and a (short) commute if you don't want to live in Camden-Lite.
I think this is quite exaggerated. Aside from Detroit and New Orleans, cities in the Delaware Valley like Camden and Wilmington have some of the worst crime in the country, because they face the challenges of other Rust-belt cities and are also on the major drug trade route up I-95.
Fully a quarter of the U.S. population lives in the metro areas of just six cities: New York, Los Angeles, Chicago, Washington, San Jose/San Francisco, and Boston. These cities are all quite safe, and the idea that people might either move into the core cities or to satellite cities in those areas is hardly ridiculous. And there's a long list of cities that are perfectly safe that aren't one of those six: San Diego, Austin, Seattle, Portland, Charlotte, etc. And there are even more cities that are perfectly safe in the areas middle class people would actually live. I lived for seven years in Atlanta, and it was very safe as long as you lived on the north side.