This means you are, at a country level, deciding by policy what jobs are desirable. Which seems to mean, according to you, that Farming and agriculture, which are generally distributed due to the land needs, aren't feasible. There are quite a few other industries that are non-tech that are distributed like these.
Sure lots of these small towns don't need as MUCH centralization as they have but they still need services because there are still people and things to do out in those places.
Now, given modern transportation and things like Amazon, the density in outlying areas may not be as needed. Driving through rural missouri, you see a lot of very tiny dead towns at crossroads, where there used to be a general store, etc, and these died in the 30s. Then you have slightly bigger towns that are dying now. These towns were starting to die in the 90s. In the 60s it took around 8 hours to get from St. Louis to the arkansas border (except along 55). When I was a kid in the 80s it took 4-5 hours. Now it takes 3:30. Because of this you don't need as many of these services as local, but that doesn't mean you don't need them.
Also driving through rural missouri you see things you wouldn't expect. My cousin owns a VERY profitable organic chicken ranch about 2 hours outside of St. Louis, near Owensville. Going further south you find all of a sudden where like 80% of the oak for charcoal and wine / burbon barrels come from. It's completely unreasonable for these folks to commute from St. Louis. It's also completely tenable for them to live in a house in the middle of no where and make plenty of money for that life style.
What seems to be happening is that much of the rural area is becoming LESS dense as you need only basic services and health care, gas food, etc.
There's also other things that need lots of space that you can easily do in rural areas that you can't do other places. If I was to switch to running a textile mill, or a machine shop, and did it in Seattle (where I live now), or St. Louis (where I used to live), I'd have to plunk down 2-5 million on a warehouse. If I did this in Wenatchee area or Owensville, the land is like $200k, and I just build the building and put that other 1-2 million into better tooling and employees, and the effective minimum wage (what people actually need to live), is a lot lower out there because everything is cheaper. Which means product is cheaper.