I don't know about relevency...
But I prefer Spotify more than Youtube...
I am a person who love to listen music during long journey, doing math, doing my practical sheets. And Youtube can't give me that pleasure. Even while typing this message, I am listening Spring Day on spotify.
And according to data, Spotify is "The biggest Music Streaming platform of the world".
I am really Happy that BTS gonna have their 1st 1billion spotify plaque soon as 1st South Korean act to do so. Early congrats for it.