Imagine the state if CTF is invalidated by the EU. I think there will be an exodus of apps from AppStore. Apple will learn the importance of developers the hard way now.
My guess is that Apple will simply find another way to try and make up for the shortfall, such as increasing the annual developer fee.
Hard to determine what's actually reasonable if there's no iOS app distribution competition to facilitate that discovery.
What do you think of the 30% cut charged by game consoles such as Nintendo, Sony, Xbox, as well as Steam?
Do developers earn more because the iOS app market is "more vibrant" (however you'd like to interpret that I guess) or simply because iPhone users on average earn more money?
"iPhone users have a 43.7% higher average salary than Android users."
And there are, as so many people loved to remind me back in the day, 4 times as many android users as iPhone users around the world. The play store would make it up in volume, and developers would abandon the iOS App Store in droves, they said.
Funny how things worked out in the end. But to your question, I would say both come together to create a virtuous cycle. Apple has aggregated the best customers in the world, which is why you see apps like notability, fantastical, lumafusion and Apollo released as iOS-only apps, because Apple makes it lucrative for a developer to focus on only 1 of the two major smartphone OSes in the world. Even games like Grimvalor, Battleheart Legacy and Slay the Spire would come to iOS first.
Meta voluntarily uses the Mac App Store along with Microsoft and Slack. Why would they leave Apple's store on iOS? Nobody spends money on WhatsApp and the last thing Meta wants is to pay more money only to make it harder to install their free apps.
One of the apps headed for the AltStore is a clipboard manager app which uses location settings to keep itself active in the background 24/7. While it does sound like something necessary for the app to work as intended, it also does not sound great for battery life (it's akin to leaving maps running in the background all day). This sounds like something that Meta would love to do with their Facebook app so it can continue to track users 24/7 and for all we know, the extra data might even be able to offset the cost of the CTF?