[flohofwoe]

It's up to the developers whether they want to sign an exclusive-deal with Epic (and of course up to Epic to offer one, because it turns out this is a very sweet deal which takes a lot of risk out of a game project, and especially independent developers would be foolish not to accept it).

Apart from Epic there are many other distribution opportunities on the PC platform. This is not the case on iOS. You either make a deal with Apple - and a very lousy deal at that, or you're not on iOS (the same problem exists on game consoles).