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’ve envisioned that possibility where Gabe dies of old age, and the company is sold to someone that will do anything for a buck. The bad news there is that any further purchases on Steam might be subject to whatever horrible practices they institute, but there’s no way they’d get away with locking off people’s existing libraries - and people would just shift over at that time to whatever other game stores make sense. And yes, other game stores do exist, even if they have smaller following.