IIRC if we track the number of downloads or songs played, even spotify and youtube outcompete torrents by a huge margin, downloaded torrents are just not that popular for music nowadays compared to streaming. The legal services took over most of the mindshare and volume of music distribution, most of the people who used napster back then now get their music from a streaming service, not on a torrent.
Spotify was spun out of private torrent network libraries that still exist independant of spotify. Youtube still gets a lot of uploads from private torrenters trying to generate ad revenue. Just because they are percieved as legal and convienient they get more views, but ultimately where did the content come from?
MP3s are so small compared to the rest of the internet now that there's a glut of shady websites that cater to people trying to get MP3s. Rings tones are a great example why someone with a Spotify account might google an mp3 for a song. Meanwhile you've got tons of semilegal mixes on Soundcloud and Mixcloud. Spotify and Apple Music is just convenience.
These sites also cater to the leaks scene. Every single hot album to drop recently was leaked 24-72 hours before dropping on "official" sources like Spotify. This makes even those people that have Spotify accounts look for MP3s.