I think Apple’s fee is more than fair for many developers. Free hosting, they do all sorts of payment compliance/fraud/tax stuff for you. To a small developer I think it’s a huge boon. But once you become BIG (Candy Crush, Fortnight, Netflix, Amazon) that advantage no longer applies. Those companies are all capable of doing all the payment stuff on their own. And when you’re doing Fortnight business that 30% is a TON…
Payments? Stripe fees are like 3-4%. Distribution? Free/non-IAP apps don't pay for this other than some licensing fees. I don't think there is a benefit that IOS/Gplay provide that even approaches being worth a 10% revenue hit, except in extreme cases.