The structure of the US economy changed faster in the past 50 years than infrastructure could adapt to. With globalization and automation, the US pretty quickl

The structure of the US economy changed faster in the past 50 years than infrastructure could adapt to. With globalization and automation, the US pretty quickly turned into a mostly-service economy and shed tons of manufacturing and agriculture jobs. Service and other white-collar jobs mean working either for or with others, so they concentrate in cities. Manufacturing and ag jobs are where the raw materials, shipping, or farmland is, so tend to be more spread out. The result is that jobs in small towns and cities evaporated and most opportunity became concentrated in large metro areas. People go where the jobs are, but the cities couldn't grow fast enough to keep up. So, yes, even though cities are more economically efficient, they are still more expensive simply because the demand grew much faster than the supply.