The focus on 5G UWB (high-band) mini-towers is mostly because that’s all the spectrum Verizon and AT&T could get ahold of early on. It’s to their benefit for everyone to think of “5G” as this super-high speed city thing.At the rate things are going, 4G/LTE may not go away until I'm dead. Heck, what can't you do on 4G? Not much. And the last thing we all need is more radiation from 5G mini-towers in front of everyone's house.
The actual useful improvements to coverage and availability of networks with 5G comes in the mid-band and low-band spectra. The speeds are not necessarily that noticeably different from LTE, but capacity and coverage can be better, which means getting LTE-like speeds in places where you couldn’t before. Especially in a country like the US.