major cities grew up for a reason. Buffalo, NY, my hometown, existed because it was the furthest you could go on the great lakes before reaching Niagara Falls. All grain was shipped through Buffalo. Bethelem Steel made iron and steel. GM used those resources to build cars. After railroads eliminated the need for a Buffalo hub, all those industries found a better place to exist.
Why Detroit? I don't see a competitive advantage.
A lot of it has to do with Canada’s industrial hub. After all, they aren’t spending a billion dollars for a new bridge to Detroit just because they want to spend money.