you are forced to pay Epic 5% of sales (if your game makes more than $1 million), so pretty much like Apple (fees are lower of course)
And I'm not arguing that apple needs to reduce the fee. They can charge whatever they want for their IAP system. But, other companies that have software/services that are cross-platform, should be allowed to use their own payment processors without paying additional fees to apple imo. Apple should be able to put up the message that hey, you're leaving our ecosystem, you're on your own, blah blah. But I don't see a reason why they should also get a cut at that point.
And with Epic, you don't have a choice if you want to use the Unreal Engine. How can this argument go on and on and on? All your arguments can be used in reverse with the Apple competitors. Nobody is forced into anything, especially not developers.
Nothing similar is the case for Unity vs Unreal; the customer base is the same either way.