In many of those places you list, much of the economic activity--maybe most of it--is actually spread out over the suburbs associated with the city rather than being within the city limits. And this was certainly true prior to a lot of large businesses moving into places like San Francisco and Boston over the past 10-20 years. [ADD: And if you do go back a few decades, there were lots of examples of prosperous suburbs and cities which, if not failing, weren't in great shape.]