I don't think 5G will be restricted to cities at all. There are some carriers who are already providing pretty good service to rural areas using sub6 fixed wire

I don't think 5G will be restricted to cities at all. There are some carriers who are already providing pretty good service to rural areas using sub6 fixed wireless. The N77 auction (3.7 - 4.2Ghz) I think will open up some very good competitive rural options. mm-wave will probably be too expensive in most cases but not necessarily always. The reason is because mm-wave being so fiber intensive. There is often a misconception that fiber is more expensive to deploy in rural areas but often the opposite is the case. Rural areas tend to have fewer regulations and restrictions that make deploying fiber a lot less expensive on a per mile basis that in cities. It's just that cities have more potential customers so it is the obvious first place to deploy. Although it will take longer to get there, I believe that fiber will work its way to more rural areas over time.