How can you ever trust something like that?

You’re missing some key facts:

1. A lot of music on YouTube is fully licensed and uploaded by the owners or Google themselves. Like VEVO music, for instance.
2. Google runs a content match algorithm on all uploads to detect music and movies. If you upload more than four seconds of a song, Google will detect it and transfer all monitization of that upload to the rights holder. This is why music documentaries like Trash Theory only have frustratingly short clips of the music they are talking about, and why channels like Techmoan, which documents weird music formats and playback devices, can also only share extremely short clips.

The rights holders are getting any and all money on music uploaded to YouTube, and your entire premise is flawed.