The countryside will never be covered by 5G. The range is massively decreased due to the higher frequency. You would have to litter the forest and fields with antennas. 4G isnt going away any time soon unless we intend to cut off all sorts of infrastructure and farmers and hikers and emergency services from internet access.
4G has a range in the 10+ km area
5G is in the low hundreds of meters range so its a fancy city tech
Isnt the bandwidth also gonna dip to 4G levels tho if you drop the frequency to those levels?