Apple demand Facebook do thing = Good for Apple (bad for FB) yes way
So Apple is allowed to get its own way, 100% of the time, no questions asked, what they want is what they get end of (by virtue of holding all the cards and owning the platform they dictate the rules on)
How about no? You can play by your rules in your sandbox, but Epic has a right to demand it's allowed a sandbox in the same park, maybe Apple will be forced to change its business if everyone starts playing in Epic's sandbox and consumers decide Apple's policies are rubbish?
That's the very definition of "competition" something Apple has avoided for over a decade at this point (as far as iOS inter-competition goes)