> you would quickly see the real value of App Store and Apple Payment processing convenience - that 30% would probably come down to 10% where it provides the convenience value.

That might be good for developers but it does not necessarily also imply that consumers are harmed. You assume that if a store charged a lower rate that the savings would be passed onto the consumer, but this does not reflect the real world where developers might simply choose to pocket the difference instead.

As an example, the Epic Games Store is charging $59.99 for the new release of Cyberpunk 2077. What's the cost on Steam? Also $59.99.