You've just re-stated my point. We've barely scratched the surface of the capability of fibre broadband, whereas we're pushing against the hard upper limit of radio frequency capability.
... but trials have, in fact, demonstrated data transfer rates as high as 40Tb/s over kilometre distances - about 40,000 times the best rate demonstrated via wi-fi over a few tens of metres.
So the hardware for truly stupendous fibre throughput does indeed exist.
