Spotify doesn't. They are free to build their own platform to access Apple's customer base. But it's an Apple made device, Apple developed operating system, Apple developed app store, which started from nothing.Holy lord, talk about blind worshiping.
Apple got "something" when you paid for that device.
Spotify is paying for their servers, internet access and everything else, why the heck do they need to hand Apple any money from that?
And if the problem is because the hold the app on their store, then provide an option to sideload the damn app.
This is Apple's system, Spotify is under no obligation to use it at all. And if users are in such disagreement with the way Apple manages their ecosystem, they can either complain loudly to Congress or vote with their dollars.