Remember exclusivity is not a PC norm. I get the idea to compare console exclusivity to make it seem less a problem. But it's not the norm on the PC platform at all, until publishers made their own platform (EA, Ubi and so on) there wasn't a divisive market outside Windows/Linux/Mac. This is not at all remotely PC friendly and even consoles have dispensed with exclusives outside in house games. Which is a move in the right direction and frankly this move on Epic's part isn't a good one. They provide a smaller cut which helps smalller self published teams. But larger scale games are paid upfront and rarely any extra money is passed down from Publisher (outside specific deals and possible rehiring for a follow up).
While 30% also seems big by comparison, for a lot of other payment methods Steams cut eats that extra cost. Where as Epic passes that on to the consumer who is forced by their own region to use alternative methods of paying. That 30% is also for everything else they provide as well, from forums, client hosting and more. They have a lot of community driven aspects like live streams (including developer live streams which are always featured on the games page, Paradox uses them a lot). Steam made PC gaming a lot more accessable to people in countries with a lacking market (like Russia), and still continually expand the gaming market every day. All while for the most part outside some specific instances they remain as neutral as possible to allow a more open market. While I get that to some that lack of curation is a bad thing, it does offer a much better over all experiance and outside GoG I think is one of the best platforms right now.
I keep coming back to this, because it's the one thing people just don't seem to ask. What will the Epic store be like when it no longer needs to pay for exclusives and it can make it's own demands? I'm more concerned with a company that wants to make a store without putting in the development time of it and would rather pay for games than work on their store. What possible end result will we have if they are like this right off the bat? Mean they make Fortnite, but they killed off every other game they have made and screwed their communities over again. So I can't see any good in their actions and only greed.