You're quoting something about “5G Ultra Wideband”, which seems to be a brand name for mmWave. Yes, mmWave has very short range. But 5G isn't just mmWave. It's in many ways an evolution of LTE/4G, supporting the same frequencies and offering the same range, i.e. multiple km/miles. But it's up to carriers how they allocate their frequencies. To quote Wikipedia:

> 5G can be implemented in low-band, mid-band or high-band millimeter-wave 24 GHz up to 54 GHz. Low-band 5G uses a similar frequency range to 4G cellphones, 600–900 MHz, giving download speeds a little higher than 4G: 30–250 megabits per second (Mbit/s). Low-band cell towers have a range and coverage area similar to 4G towers.

— https://en.wikipedia.org/wiki/5G#Overview

5G is _perfect_ for providing coverage in rural areas, except for the problem that 4G devices are incompatible with 5G networks. Starting 5G rollout in urban areas makes more sense because (a) 5G provides most benefit when clients are close together, and (b) because denser cells make it reasonably economical to maintain 4G coverage in parallel to 5G coverage.