Try tilling 40 acres with a horse. Imagine getting sick, or giving birth.
We lived without cities, but with a vastly lower population and quality of life. Things like knowledge work and financialization are what made possible great ventures such as energy distribution, transportation, mechanized farming, medicines, and so forth. I'm not sure agriculture would even sustain the existing rural population without the infrastructure of a complex modern economy.
We're all in this together.