Developers are free to delete their apps from Apple's store ar any time. Yes, apps bolster their own pockets, but they also bolster the pockets of the developers themselves.
Devs might have deleted their apps from AppStore, but Apple literally doesn't allow to distribute software any other way, and even in the EU where it oretends to allow competing AppStores, it still interjects itself into the process
Apple owns ios, Apple owns the iPhone. It would make sense that those factions within Apple would still be involved even if the AppStore people are not.
