I see some larger publishers bemoan the fact that Epic hasn't caught on, but it should be pretty obvious why. Markets that favor the buyer more than they favor sellers will typically attract the largest user base, and the sellers don't have a choice to not sell where the buyers are.
Epic giving away free games is a nice buyer friendly action, but literally everything else they've done, from paid exclusives to poor client experience isn't favorable to buyers. They've created a market that no buyers want to use unless the product is free or literally not available anywhere else.
Giving publishers/devs better cuts is great, but it does nothing for you if all the buyers are on Steam instead.