Must be a reason "not too many AAA stations exist." Could be because the format can't get arrested in most markets.Hard to tell because not many AAA stations exist. They would certainly do better than what passes for Alternative these days. Someone who was 18 in 1990 is still in the "Saleable" demos. They grew up on the music I mentioned. It's ridiculous to say that Classic Rock appeals to 40 year olds, but 90s music doesn't...
Listeners will tell you that they want to hear new music... as long as it's new music of the genre they like. The listeners' tastes are fragmented, and as a result, AAA stations can't get the traction required to generate revenue. You'll hear sentiment like, "Man, that was a great station!" Yep. Great station. It couldn't break a 1.3 share and after two years, went away. Oh, but it played great music. I loved it. Too bad the music you loved didn't appeal to more listeners.
Know where most radio listeners are getting new music they like? On country format stations... where most of the music sounds like 70s and 80s Skynyrd, Marshall Tucker and 38 Special tracks. That's another thread unto itself. Country music has really taken such a turn... Save for a few artists and groups, it "bros, boobs and brews."
New music from legacy artists and groups doesn't attract younger listeners simply because the songs are new. Preconceived notions play a big part in determining why listeners reject new music from legacy artists. Take Paul McCartney, who put out a new album last year. It hit the charts top five, and then disappeared. It had a few noteworthy tracks too, but younger demos viewed the music as "the guy my parents (or grandparents) listened to." And the upper demo crowd didn't rush out in droves and buy it. "Oh, McCartney's great ... I like his old stuff. That's why I went to see him." Yep. They want to see and hear him play Maybe I'm Amazed, Junior's Farm, Wouldn't That Be Something, Hey Jude, a bunch of Beatles tunes, Band On The Run and Jet. The new songs? Not so much.
Go to a legacy music acts show ... that is, if legacy artists and groups maintain their tours, given the risk of covid-19 ... and you can see that a substantial number of people go to the concession stands or the loo when the artists/groups do their new material. Concert goers go to see their favorite acts mostly to hear the hits. It this way, it's very much like radio.