https://www.techdirt.com/articles/20210429/09400646702/epic-effect-microsoft-changes-revenue-split-to-match-epic-store-steam-holds-firm.shtml

Way back when Epic released its Epic Store PC game storefront, the release of this new competitor to Steam focused on two major selling points. The first was timed exclusives that it shelled out tons of money for, allowing it to sell games the public couldn't get anywhere else for a certain period of time. This pissed off lots of people, as the public generally doesn't like exclusives. That said, Epic did mention that it would end its exclusivity practices if the rest of the gaming storefront world, especially Steam, mirrored the Epic Store's second key selling point, which was a far more favorable split offered to game developers than the "industry standard" 70/30 split that sees places like Steam getting nearly a third of game revenue just for hosting the game on its platform. Instead, Epic's store has a 88/12 split, meaning the platform is willing to take less than half of the revenue Steam extracts from gamemakers.

In other words, Epic positioned its exclusivity program as merely a method to get the other storefronts to take less money away from game developers, which softened the blow with the public and surely made it a great many fans in the gaming industry.