Chicago's crime rate isn't nearly as high as it's made out to be. At least according to wikipedia, it's ranked #10 on murders (behind places like Kansas City, Cleveland, and Memphis) and #17 on all violent crime (behind places like Minneapolis, Kansas City, and Albequerque)
Your perception of the success of cities seems to be rather skewed. Urban areas are the engines of our economies. They create more economic output and enjoy more economically vitality than non-urban areas:
Another Clinton-Trump divide: High-output America vs low-output America
https://www.brookings.edu/wp-content/uploads/2018/09/PBP_FramingChapter_compressed_0928.pdf
A couple things:
I don't know where you got the idea that the Baltimore metro area has 7 million people, but it doesn't. The whole state of MD only has 6M. Baltimore Metro has 2.7M. The city itself has 600k.
The poverty in Baltimore also has to do with de-industrialization. Baltimore was built as an industrial town and got socked pretty hard by the closing of Bethlehem Steel, GM, and a number of other factories and harbor facilities. That, combined with some pretty egregious white flight throughout the mid 20th century left and generations of corrupt and/or incompetent politicians have left the city in rough shape. Harsh policing strategies exacerbated all of that.
I don't know why you're calling out northern Baltimore specifically. That's the rich part.
The lack of public transportation, or even of decent highway transportation, doesn't help either.