Too many commercials. Listeners have been saying this for years. But most corporate radio has ignored that.
The number of commercials on stations hasn't changed in over 30 years. What has changed is the placement. At one time, commercials were grouped in 3 or 4 breaks. After PPM was added, research indicated two breaks an hour was best. But the number of spots is the same. This happened 20 years ago. What's changed is the audience tolerance for commercials, and the quality of the advertisers. Nothing radio stations can do about that. Advertising is the only source of revenue for radio. The other option is having the listeners pay directly, the way public radio does. If commercials are driving listeners away, then the public non-commercials should be top rated in all markets. They aren't.
And the lack of personalities on stations. The corporate companies gambled that listeners wouldn't notice on air people mysteriously disappearing from their favorite station. And replaced by an out of town voice or worse...no voice at all.
It depends on the format and market. Some formats are music intensive. Some aren't. Certainly talk & sports stations still have lots of personalities. That hasn't changed at all. CHR, country, and urban stations are still staffed with personalities. What's changed is a lot of heritage personalities have either retired or passed away. Nothing radio stations can do about that. People get old, and at some point stop working. The replacements are younger and appeal to younger audiences.
Where are radio listeners going? Streaming services that have no personalities at all. If the audience really wanted personalities, they wouldn't be going to music services like Pandora or Spotify that have no personalities.
When asked if they listen to radio as much as they did five years ago, the majority says no. When asked if their favorite radio station is as good as it was five years ago, the audience says no. Until radio ownership is ready to address the personality issue, radio's slow death will continue to happen.
Who did the asking? If you're going to cite polls, you should post the links here. The fact of the matter is there are many things causing listeners to leave broadcast radio. One is the ability to make their own playlists. Nothing radio stations can do about that. The other is eliminate commercials by paying a monthly fee. That option isn't available in broadcasting. The third is that digital devices are more available and convenient that AM/FM radios. Nothing broadcasters can do about that.
Corporate owners are transitioning from broadcast radio to digital services. They're creating podcasts that are entirely based on personalities. The podcasts have limited commercials too. Yes people are using broadcasting less. Radio companies know that. There's no amount of staffing stations can add that will cause listeners to throw away their phones or digital devices. That's why stations are redirecting their resources to platforms the listeners prefer. Perhaps you should sample them.