Most are a holdover from a time when we were a manufacturing powerhouse with waterways as our main transportation; unless they are a major port today, they can be replaced with office parks.
NJ’s biggest city is basically a transportation hub for trains and planes, with a large port - surrounded by a couple of hundred thousand dangerous, idle people. The offices downtown are a small segment of the larger city, and have a difficult job attracting talent; while they aren’t near many residential areas, the mutants go there to disrupt things because they know it is the only way to get publicity. Some areas destroyed in riots in 1967 weren’t even rebuilt; there is no reason to do so.
Many years ago I was required to go to downtown Newark for a hearing in front of the public utilities regulators.
I was living in CA at the time so I had to stay overnight at a hotel downtown.
It was the only time I ever saw a security guard standing by the check-in guest with a huge rifle by his side.
He explained “do not go out after dark”—and I believed him!