I think it is both of those things, as well as the nostalgia thing a previous comment mentioned. I tend to hyper focus on a band or artist I like and listen to them non-stop for a long period of time. But I also will listen to a curated playlist of a bunch of different genres. They could be a band I discovered in middle school, or one I discovered in the last month, but something hooks me and I'm there.

Music has this wonderful way to bridge all the divides of humanity. You don't have to speak a foreign language to appreciate a song in one. And whatever you are on the political spectrum, there is at least one song we can all agree is a banger lol. People of all different backgrounds will like the same artist. For me, music unifies us. Maybe that's why I listen to it.