Earlier quoted context omitted.
Because this isn't a tax on web purchases. As a developer you need to pay the 30% commission similar to how if you're using Unreal Engine you need to pay 5%. You can legitimately argue this fee is way too high but the courts have already said that they are allowed to charge it.
I don't think the issue is how high the fee is, the issue is Apple forcing developers to use their payments platform. Apple is within its right to charge whatever they want. Unreal Engine is free to charge whatever fee they want. But you're not forced to use UE. You are forced to use Apple IAP system, or their alternative now, is to allow you to use your own system, but still pay them a ridiculous fee, for what exact…
Apple charges 30% if you do choose. Epic charges 5%.
Apple argues that what you're paying for includes SDKs. Epic does too.