They being the largest platform because the consumer wanted their service, not out of obligation. Epic provides cheaper cut for the developer and is steadily building up their library. But why don’t users flock there? Heck, they even have some actual exclusive titles there. EA and Ubisoft too got their own store, and they too got a few exclusive title. So why does steam is still being chosen? Maybe there is other value provided besides hosting, like, idk, remote play? Controller remap? Family sharing? Opening linux gaming market? Social feature? Forum? Modding?