Don't know for a fact. Do you know? Suppose, there wasn't an App Store, or iOS users could still use the Spotify app. I just don't know.
Now, its quite obvious that Spotify customers use iPhones as they use other devices. How could you use any digital services without a device ... the Internet is not yet embedded on peoples brains. Are you saying that Apple seams to be using iPhone owners to charge whatever they see fit to Spotify and others? Agreed.
What I don't understand is this. Apple is a fabulous company. The iPhone and iPad are really good devices. It granted them an evaluation of trillions, allowed them to develop new Digital services ... Apple Music and so on.
I don't understand how the practice of blind charging third party digital services for things that the App Store does not service, sell or promote as if they did is good for customers in general ...
I mean, you just said it your self with your rhetorical question. Spotify users using the iPhone, people that like their service, would not benefit then from Spotify leaving the App Store without their App. People that already payed thousands for their Apple devices. These people would either need to sell the device they like to use and go for something else, or use a service that they don't prefer ... Apple Music or something else. This kind of leverage Apple has over third parties, using their device market share, can be clearly anti-competitive. Congrats ... you figured that one out