It's because the music "industry" controls every bit of music on the airwaves, and it's all the same stuff, because it's cheap and easy to produce. They also control who has hits and who doesn't, so the only things that get promoted are those that they fully control. Modern "popular" music sucks sweaty unwashed donkey balls on their best day. And the radio sucks cuz of it.
If you want to find music that's good, you gotta delve into the stuff that doesn't get actual airplay. The various kinds of metal, jazz, classical, and other genres of music that seem to be limited to YouTube or Bitchute or other places. Look around, you will find TONS of music that you never though existed!