Outside of cities there is no use for large spectrum for 4G and 5G
Outside of cities, there is not much use for this much spectrum. This is country specific. More dense countries require maybe more spectrum, even in rural areas. However. I don't think they require this much spectrum. They are overestimating the usage of 6G by a factor of 100, even more in my view. For less populated countries. Like those in the Nordic region (where I am from). None of this high frequency spectrum is going to get used. They currently barley use the n77, n78 in many parts of those countries. For both 4G and 5G, usage in band 8, band 20, band 28. Depending on the licence that the mobile network has.
Here is all the spectrum that has been allocated for 4G and 5G. As they turn off 4G with time, along with 5G. All that spectrum is going to be free for 6G when that time arrives. Currently, old 2G and 3G services are being turned off in the Nordic countries. Plans are not the same between countries.
https://en.wikipedia.org/wiki/LTE_frequency_bands
https://en.wikipedia.org/wiki/5G_NR_frequency_bands