The challenge for many American cities is that our infrastructure allows for greater competition between cities now.
The major I live near is Cincinnati, Ohio. It has shed people nearly every year steadily since it peaked in 1950 to now be back at 1890 levels and has never been able to adjust. Why? Because people fled to the surrounding areas, and then businesses and tax revenue followed. Boom towns like Florence, Kentucky or Mason, Ohio grew up because people liked things such lower taxes, lower land and housing prices, better schools, etc.
Cincinnati, like Detroit on smaller scale, has struggled to adjust to the fact that they have to serve and market themselves to people and businesses. Why do you visit a city? Why do you want to live there? Why do you want to do business there?
The thing is, as people pointed out, these issues were seen decades ago in Detroit. Yet major reform never happened and they will pay for it likely with brutal austerity as one generation sacrifices for the poor planning of the previous ones.
