Funny that Epic, Spotify etc don't complain about the same cost levied by other platforms like Playstation, Xbox etc?

Usually the strategy (mostly, but hardly exclusively, followed by patent and other trolls) is to start with the smallest, weakest participants and then use them as a precident and then work your way up.

Starting with the richest of them all with decades of litigation experience seems foolish, and indeed it hasn't worked for Epic. Also a lot of people admire Apple, so why face that in the court of popular opinion when you could have build the case that they are the bad guys?

FWIW: I think Sweeny is a dick, that Spotify is financially precarious, and Apple is basically a great white: efficient, relentless, and not your friend.