The Epic First Run programme allows developers of any size to claim 100% of revenue if they agree to make their game exclusive on the Epic Games Store for six months.
After the six months are up, the game will revert to the standard Epic Games Store revenue split of 88% for the developer and 12% for Epic Games.
I 100000% believe your comment on the pre-existing library is why they give free games away weekly. They want you to build a library that you then won’t want to move from which is exactly why I too don’t like being forced to buy things on another game store. I don’t like exclusives no matter where they are, it’s anticompetitive bullshit.