> They obviously do this because they want you to download the YouTube app which has its own picture-in-picture mode and advertisements that are more difficult

> They obviously do this because they want you to download the YouTube app which has its own picture-in-picture mode and advertisements that are more difficult to block. They do it because their agreements with the record labels prohibit it, as the labels do not want YouTube to be a free Spotify competitor. It appears that YouTube recently have made a little bit of ground convincing (or at least are doing AB testing in the hopes of convincing) the labels this doesn't happen and enabling it in the app, but there's no anti-trust concern here as Apple would have the same issue. Indeed, I suspect the reason Apple do not raise a stink about it is because they do not want to endanger their relationship with the labels for Apple Music.