You're not wrong, but this doesn't just happen in America, and it doesn't just happen at the city, county, or state level.
There are entire countries or overseas departments of countries that cannibalize tax bases of others, some in corporate taxes, some in personal taxes. There are countries that, due to low wages, low cost of living, and low worker protections, can manufacture certain goods really cheap. There are countries that can ruin their countryside extracting resources like copper, rare earth metals, or oil and sell it internationally.
Ultimately regardless of what the territorial unit, each unit looks out for their self-interest, because a 'Unified Greater Boston' may result in more growth, but it will likely come with a different allocation on wealth to the particular area that each fiefdom covers. It's really just capitalism where each entity competes with another, and some win really big, while most don't.
As an example of a better situation, London covers the cities and many smaller towns and suburbs, which each have their own local government. The local areas are responsible for schools, waste, most planning etc.
But it's all unified under the Greater London Authority, which controls transport and policing. This is what the Mayor of London controls, as head of the elected London Assembly.
There are entire countries or overseas departments of countries that cannibalize tax bases of others, some in corporate taxes, some in personal taxes. There are countries that, due to low wages, low cost of living, and low worker protections, can manufacture certain goods really cheap. There are countries that can ruin their countryside extracting resources like copper, rare earth metals, or oil and sell it internationally.
Ultimately regardless of what the territorial unit, each unit looks out for their self-interest, because a 'Unified Greater Boston' may result in more growth, but it will likely come with a different allocation on wealth to the particular area that each fiefdom covers. It's really just capitalism where each entity competes with another, and some win really big, while most don't.