It’s the only income they receive in that case, and it is fixed, whereas their costs are variable (e.g. whether some app is downloaded thousands of times or doz

It’s the only income they receive in that case, and it is fixed, whereas their costs are variable (e.g. whether some app is downloaded thousands of times or dozens; whether apps decide to post video previews or not; they receive the same money but incur different costs on infrastructure). App Review alone takes hours per update and is done many times a year for apps. Even if a single Apple employee is involved, and even if they are paid something pathetic like $5 an hour, that $99 will be eaten up quickly from reviews alone. My point is that it doesn’t add up; Apple likes to claim all these “costs” for “running” the App Store but there are gaping holes in their accounting unless you consider that not all developers are really equal here.