Having worked on an app that took payments (although I only ever personally did work adjacent to the payments), customers from the Apple App Store seemed to be more likely to have the ability to make payments; they were likely to have a working payment method on file with Apple. We were a low priced subscription though, 30% seems like a lot, but straight credit card, card not present processing isn't much better when you add the fixed fee to the discount rate. It's better if you can get a micropayments rate, but we couldn't. Lower friction often means more payments, so we would certainly not leave platform app stores to get more control of payment (although, the direct downloaded apps might include more payment methods)
