> Now they have an unfair advantage since Spotify must pay 30% to apple while apple music "pays" 0%.

I think this does not account for the opportunity cost. If Apple Music competes with Spotify, then Apple Music implicitly pays the 30% fee of the next best alternative. If Spotify operates at a loss with the fee, and Apple Music is otherwise an identical business, then Apple should prefer Spotify - it makes more money this way. The fee is basically irrelevant.