This is where you and I would differ. For you, radio, TV, and the new media (streaming, podcasts, etc.) can be lumped together as one "the media," and therefore there would be no monopolies created should the FCC remove all AM and FM ownership limits. Also, your viewpoint (as I understand it) is that since there is less audience for over-the-air broadcasting, then broadcasters should be allowed to grow and become monopolies to serve that smaller audience.
Please look at this issue from the point of view of the media consumer. A person has all kinds of audio choices, including AM and FM radio, satellite radio, podcasts, streams with commercials and streams without commercials.
When a person wants to hear something, they don't think "Oh, I guess I should listen to an FM station". They think about where their favorite music, news, talk or sports content is found. In 75% of the cases, they do no go to an over the air radio station.
One of the interesting legal battles recently involved the proposed merger of two of the biggest supermarket chains. However, the discussions on "market share monopoly" failed to include the grocery departments of Walmart and Target as well as the online grocery shopping with Amazon and Walmart (again) and smaller internet based grocers.
When my family buys groceries, almost all the non-frozen items are bought through Amazon and Walmart. They bring them to us at about the same added cost of time and use of our cars. For us, and many other consumers, the options include all sources. Just as in audio services, consumers look at their available panorama.
As BigA said, folks no longer take a little radio with them when they leave home. They have "radio" on their phone.
But I disagree with your starting point. AM and FM radio are separate from the so-called new media and should be treated separately. Why? Because of the limitations on available frequency space on AM and FM, something that does not apply to the Internet.
Again, look at this from a consumer perspective. We have thousands of audio options, and only in 25% of occasions do we look to radio.
The number of frequencies on both the AM and FM bands are limited not only by law but also by practicality. There isn't space enough, even if you allow the much narrower separations between local outlets like Mexico does,
Nearly every nation with full commercial broadcasting has the same separations (second adjacent local channels) because they are not encumbered by FCC rules written or based on 40's and 50's receiver technology.
to have unlimited broadcaster ownership on these bands and still allow new entrants. And when you fill up all of the available frequencies in a given market with stations all owned by the same owner, then you have created a monopoly for that market, even if that monopoly isn't national.
How is there a monopoly when radio only captures a quarter of all local audio listening.
When Sherman and Clayton were passed, the concern was not about how big the audience was (commercial radio hadn't entered the picture yet) but the power over pricing and the behavior of others that monopolies could allow for their owners.
Again, from the consumer perspective, radio is now very secondary.
Compare that with the Internet which houses the new media. While there are a few limitations, there are virtually no limitations on new entrants since no over-the-air frequencies are used. The major limitations have to do with the cost of using copyrighted material over the Internet (high and probably will go higher) and the cost paid to streaming providers (relatively low as I understand it). In the Internet world, you don't have to worry about monopolies and monopolistic competition because the price and availability for new entrants is (relatively) low.
And licensed AM and FM stations have to compete with audio competition that has certain advantages over them, including the ability charge users for their service. Eventually, those non-AM and FM services will disappear entirely because they only have one revenue model and huge restrictions that any other service does not have.
No, the rules (not many) used for broadcasting over the Internet *should not* be used for over-the-air broadcasting again because of the limited number of frequencies available for the latter. And the current size of the over-the-air audience shouldn't be a part of that discussion.
From the listener perspective, it's just "audio". The more you restrict AM and FM station owners from creating viable operations, the sooner the whole sector will die.