Background play is bloody annoying if you don't use YT for music. I prefer videos to stop when I switch apps, then resume when I switch back. Now they keep playing.
And I'm starting to get recommendations of music that I can't remove or tell it I'm not interested in.
Every report on piracy I read points out that the biggest pirates are also the biggest spenders on “legitimate” media, streaming, cinema tickets. This will only increase purchase of such things by a rounding error. It won’t be the money spinner they’re hoping for. It’ll reduce the number of people that view shows & movies, and have a more significant effect on viral and organic hype.