American music on radio platforms

It seems like all rock playlists are made up of the same songs. Is there a service that picks something truly unique?

Yes. I am also tired of listening to the same set of songs, even when I turned on "personalized" selections. And here https://kuasark.com/en/countries/united-states/ radio is not focused on popularity, but on uniqueness. You can find rare concert recordings, forgotten bands and even subgenres that are hard to find in regular recommendations. If you want to break out of musical monotony, try listening to their stations!