I would be more than happy to pay 30% for sales through the Apple App Stores if they were first class for both customers and developers. But until we get there they have to fix a lot of problems:

1) The search algorithm is less than mediocre. 100 chars of keywords are ridiculous, especially for languages with long words and flexions like German or French. And a mere 21 categories are not nearly enough for customers to find their way around a complex software landscape.

2) Requesting more money for ads to improve problems with search keywords is impertinent and is leading to an arms race between developers whose sole winner will always be Apple. Using names of competing products in paid ads or keywords should be forbidden.

3) The StoreKit framework is deficient. Implementing subscriptions is extremely tedious and unreliable and the customer facing purchase UI only consists of raw modal alerts loosely popping up in any order.

4) Why are subscription apps and apps with free trials treated as if they were free? This is deeply wrong, confusing, and is leading to a load of problems like unwarranted bad reviews and unfair placement in the charts.

5) Apple does not offer a path for paid upgrades but at the same time limits the types of apps that are eligible for subscriptions. This severely restricts business opportunities for a lot of apps.

6) Why can anybody write a one-star review about a subscription app without ever having used it or written to its developer support? Even Amazon has a concept for verified purchases.

7) Why can't developers attach searchable text captions to app screenshots in the store? The screenshots are required to perfectly match device sizes, but everybody shifts them around to make room for informative texts.

8) Why is the app store ignorant about dark mode? When running a dark app store one still has to squint at light screenshots even when the app in question supports dark mode.

9) Why do developers don't get to know who purchased their apps?

10) Apple does not care about professional or business software. The Work category in the Mac App Store for example is extremely low volume and contains apps like Carrot Weather or Delicious Library and has been featuring the usual suspects for years.

11) Not every app fits into the crude concepts of the app sandbox. Apple knows this, because its own Logic Pro isn't sandboxed at all but is still allowed in the app store. Some apps are somehow more equal than others.

12) Apple should turn its frameworks and tools back into kits of really composable and extendable parts. Instead they succeeded to shrink the amount of possible overrides and delegations in their APIs to a bare minimum since the NeXTSTEP days.

13) And why on earth do I have to pay $95 a year as a developer if I already have to share 30% of my revenue?

Until these points are resolved, I suggest that Apple reduce its share to 15% for apps and in-app purchases and to 10% for recurring subscriptions.