Does BitTorrent fall under that? Or YouTube? Plex? Google Drive?

BitTorrent, yes.

YouTube, no. They take down videos with copyrighted material.

So by extension browsers allowing file downloads also falls under that? That's just what BitTorrent is after all.

And knives. They can be used to kill people too.

You can also say it benefits the artist because it makes it easier to listen to them, which incentivises people to give them money to support them. This is more or less the entire model of Bandcamp.

You can indeed say that - and people who demand artists work for "exposure" often do.

But there's no evidence it's factually correct.

And Bandcamp's model is based on selling tracks and albums with free previews, which is entirely different to free listening.

Right, and Bandcamp is probably the most pro-artist of the major music platforms, I would say. The project also benefits the artist but creating an infrastructure not controlled by Youtube or Soundcloud.

Source?