Boston & San Fransisco have the surronding high tech industries to bolster them. Silicon Valley types go there to live.
Detroit’s main industry — automobile — is no longer viable. Also white flight drove out the tax base (I can’t blame them for leaving, though). I’m not an economist, so I can offer no knowledgeable solution.
Maybe if the city created something else to attract money or talent? AND drove out other elements. Basically the whole city would have to be restrucured. (In my dreams.)
The automobile is no longer viable? People are driving more cars more miles than ever before. And these cars are all made or assembled in America. Boston and San Francisco suffered white flight but now are going through gentrification. Detroit not so much. As far industry goes the only thing replacing manufacturing in Boston and San Francisco is health-care and higher education. Neither of those fields have replicated manufacturing tax income. Yeah, they cleaned up the boarded up buildings and provide jobs and housing. But the tax drug the over unionized cities crave is not being produced at the old levels.