[hakfoo]

The idea of "only one transmitter" might have made sense in 1950 for analog signals with no chance of replay, but I have to think we've learned a lot about multiplexing and collision detection.

If we allocated broadcast bands today, would we have a hundred narrow channels, or would we have a smaller number of channels and use a TDMA or CDMA style system to expand the number of available slots? I could even imagine packetized broadcasts-- rather than "KXYZ-FM" being on 98.6, your receiver would just scan the entire band for packets tagged KXYZ, and they could dynamically reallocate based on local noise levels or atmospheric conditions.

[RF_Savage]

That sounds a bit like DAB multiplexes. Except that there is a single transmitter and you buy a slot in it. Cognitive radio with dynamic frequency selection was all the hype along with TV white space radio. But the only actual service that has materialized was the 3.65GHz CBRS one. And that seems to only have been successful thanks to it sharing frequencies with the 3.5GHz 5G bands, making equipment available and affordable.