5G tower on every city block to be effective.
Seriously? Egad!
That is need so the ‘hidden persuaders’, can monitor your exact location in real time.
Also faster internet on the micro size screen of your phone.
And do not overlook all the employment opportunities manufacturing the new phones.
Looking for a job? Do you speak Mandarin Chinese? Cantonese?
Roughly, the more information you want to put over a channel requires higher frequency. Higher frequency is more line of sight than lower frequency. Hence the need for more closely spaced transmitter/receivers.
Roughly.