Have they not taken AMTRAK between New York City and Washington, D.C., passing through the industrial back lots of Baltimore, Wilmington, Philadelphia, Trenton and Newark?
To be fair, that's mostly because of Democrat "leadership" in those cities.
Lots of other areas have re-invented themselves, but you don't hear about that.
Manchester right near me used to be a mill city...the textile capital of the US, at that. Tens of thousands of people worked all day and night in the waterpowered mills. The mill industry completely collapsed. But...the buildings aren't "bombed". All those massive brick mills along the river are brightly lit at night, they're office parks, restaurants, multi-level lawyer palaces, hotels...and a former meatpacking property is being rebuilt as a huge research and medical complex.
Some means of manufacturing get outdated, and get replaced. Fifteen years ago, my "computer" was a big, clunky beige box that made noise, with a big CRT sitting on the desk. Now it's a 1" piece of aluminum that's thousands of times more powerful. The old, clunky one is junk.
You have to figure out what to do with the junk. Recycle it somehow, or leave it there gathering dust and falling apart.
Some cities are well-managed, and do it right. Others do not.