UWB is very low power, with a large number of pulses of very low amplitude typically below the
noise level, over a large bandwidth (minimum 500 MHz).
It's not just the bandwidth. UWB has a peak power density limit of −41.3 dBm/MHz. 5G is 55 dBm.
Note the many, many, many orders of magnitude difference...
Think video delivery kiosk - I'd like to rent a movie please or I'd like today's daily news videos/VR. Downloaded in 3 secs from a vending machine?