[Retric]

Farming used to take a lot of manpower. So, the industry was largely what's going on between these small towns.

Cars reshaped the landscape as stores / restaurants / movie theaters etc could draw from a large enough population to support themselves. However, farm automation drastically reduced the number of jobs causing young people to move out. Eventually you can't really support much, but the travel distance allows for some shops in these nano towns.

Remember, 80 acres used to be a viable small farm. Now 800 acres are generally just a hobby unless your raising livestock and buying a lot of feed.