> B) If this does happen, then just make the choice of not installing the app.

Why is "If you don't like the app spying on you, don't install the app" OK, but "If you don't like paying the 30% tax for having your app on iOS, don't make an iOS app" not OK?

Because it affects a third party, the consumers who gets less choice. I admit that the tax is not a legal problem by itself, companies are allowed to act selfishly.

It is a legal problem only when the Apple tax becomes anti-competitive behaviour by giving Apple products an unfair advantage (e.g. Apple Music vs Spotify). Apple driving away from the market competitors to its products is bad for everyone but Apple.

How to solve that? 3rd party app stores are workable and theoretically desirable, but that's a solution both Apple and the 3rd party stores will end up hating without fixing the problems (95% of users will still only use the official store; Apple will still hate it because they lose 5% control).

It's better to fix the current store. Perhaps banning use of private APIs by non-system Apple apps and allowing payment system choice would be enough. A more transparent app review system would also help.