I happen to have some knowledge of radio. Lefty talk, where it got a hot stick (good antenna and respectable signal), did quite well. In my market, the progressive talk station did just fine.
Advertisers, who got it, would support the station. We had a couple who paid well, and got results.
Dirty secret in talk radio: most owners are conservative. Deffo bias there. In my market, the progressive talk station got next to nothing from the owners. Rightie talk got tons of cross promotion.
Where a leftie talk station was not owned by a major cluster, it also would do just fine.
In mainstream media, there is a basic conflict of interest. Flat out, big business does not air progressives, because progressives would cost them and regulate them.
Online, the majors are making a push to get relevant with younger people, who now call them legacy media. (Gotta hate that if you are CNN)
Access journalism, actually a basic fail to do journalism, for fear of losing access, coupled with the same big business bias, means we do not produce economic left content in major media in the US.
Some of this "extreme" discussion centers on the fact that big business simply does not want that on the air, or in people's feeds.
Progressives struggle with this constantly.
Labor just is not in most big platform interests, and many younger people simply ignore the major media for this reason.
I, at a much older age, get pushed to watch legacy media online every day, multiple times per day.
I do not want to watch them. I want more about ordinary people, labor and the political movements seeking better.