Music has become more stratified. The 90s through the present have been an ongoing escalation of music being democratized more and more, from the rise of the DAW in the late 90s to iTunes and P2P sharing to YouTube and music streaming. So there is vastly more music now, and people have more opportunity to find things that suit their tastes.

People listen to a wider variety of music and the same Billboard notion of popularity doesn't really paint a useful picture anymore. What plays on the radio or in TV ads is the lowest common denominator corporate waffle, and is played heavily, but it doesn't represent what people listen to overall.

I have personal playlists of everything from House music and 90s Eurodance to all kinds of J-Pop to 19th century folk music to early 2000s rock to 80s synth pop to orchestral music. I couldn't name a single Taylor Swift song offhand, but apparently she's pretty big.