But why could you not just keep using the AppStore and nothing else? Out of the things you've listed the only one who would actually consider leaving the AppStore would be Epic.
Take Amazon’s Audible as an example. I use that. I want to continue using that. If Amazon launched its own store on iOS, does that mean they stop distributing it on the native App Store? If they do make it exclusive to their store, I will have to download their store.
I really don’t like the 30%, but that I see the line Apple shouldn’t cross. Loosening restrictions or opening it up for more stores effectively means the iOS platform wouldn’t be worth What it is now.
Facebook has been pretty vocal about iOS privacy restrictions as well. They don’t need to make their own store on Android; but they very well might on iOS.