Costs of deployment for new networking technologies tend to decline over time as we learn how to avoid unnecessary redundancies. Deployment costs of fiber-to-the-home networks declined to about 20% of initial levels over the first three years of deployment.
So yes, 5G is over-hyped the same way that all breakthrough technologies are over-hyped. The market will ultimately shape it, and we will also find new applications that the marketing folks do not anticipate yet. So in that sense, 5G is also under-hyped, just as breakthrough technologies always are.
You can count on rural networks being built out of a variety of wireless technologies in present and near future. As needs for capacity increase, signal processing systems that enable more efficient sharing will keep the rural folks ahead of the tsunami.