Re: How did they come up with that value
Most users has NOT spent money in the App store.
If 15% is fair, then everybody could get 15% of their purchases back - limited by expiration of the claim.
And if 15% is fair, we need the same everywhere. Microsoft store, Epic store, Playstation Store etc. Personally I think it is dagerous to set a rate.
If developers are not happy, they just drop the Apple app store. And Apple will come to them if they want the product on the shelves.