Re: How did they come up with that value
"And if 15% is fair, we need the same everywhere. Microsoft store, Epic store, Playstation Store etc."
No, we don't. What we need is choice, and limits only if there isn't choice. If the Microsoft store charged 99.5% (and they don't, it's 12%), that would be fine. Why? Because you don't need to get apps from that store and most commercial ones aren't there at all. If they wanted to charge that much, all commercial apps would leave and they'd have to decrease it to compete. Apple's is different because they've denied other choices. I agree that, if their commission is too high, anyone else with such a monopoly on distribution should have the same action brought and their commissions reduced as well. It would probably be better for everyone, including Apple's profits, if they allowed different installation mechanisms instead.