Revenue is down. Way down over the decades.
Of course it is. You take a neighborhood with one restaurant and add ten more, and the revenues at that one restaurant will go down. Regardless of quality, regardless of price. More competition lowers revenues. That's basic economics. There is no reason to believe that adding more songs to the play list, or more talk from the DJ will improve revenue. That's simply wrong. Lower revenues is not a programming problem.
Creativity among jocks, especially morning shows: I have found management typically does not want to get away from what research tells them to do.
Here's what I've found: Management wants what works. If they have a morning show that makes money, all the rules go out the window. The station will fire everyone else to pay for that morning show. Top morning shows don't report to the PD, but the GM. Top DJs have personal agents who work directly with management and ownership to ensure their client is the best paid, and gets to do whatever he wants. All that is great and wonderful until that DJ says something that pisses off a community group. Then everyone gets fired. That's how radio works. On the other hand Joe Rogan says something that makes national news, and Spotify leaves him alone. Why? They're not licensed by the federal government, and their money comes from subscribers, not advertisers.
You make an interesting point about trying something new. Here's what I have found: the one that tries something new is the least among stations in a market with nothing to lose
I've worked for both commercial and non-commercial radio. You have too, I believe. I think we can both safely say things are very different in the non-commercial world. If someone has an unusual idea, and it can get funding, it will get done. We had an organization come to us with a weekly poetry show. Every week, we'd spotlight a different poet reading their poetry. Try doing that at a commercial station. We did it, got it funded, and it ran for a while. But advertisers in the commercial world want one thing: numbers. I was in a sales meeting with a creative programming idea, and at the end, all the sponsor wanted to see was "spots & dots." The brick wall in creativity on the radio is with the advertisers. They determine the size of the playlist, the format, and the amount of creativity. That's why I say if someone wants more creativity in radio, they need to listen to non-commercial radio.