@Gargron I read (lightly, so feel free to correct if I misread) that app distribution will still happen using Apple’s infrastructure and as such applications will still need to abide by certain limitations like no malware and such. They are getting rid of the 3% processing fee if you use other payment processors (this would be what credit card companies take + ~.5% I assume they are counting towards compliance, infrastructure, and profit).

Now is their infrastructure worth 27%? Very debatable.