The way for Epic and other developers (especially game developers) to bypass the app store walled gardens and associated distribution tax is to go through the open web instead, delivering their software directly to consumers. Leveraging new bleeding edge browser technologies such as WebGPU and WebAssembly, it's going to be possible to distribute games and applications online that can run at near native performance as webapps. These webapps can then be pinned to the homescreen for an even more authentic app-like experience.
Yes, WebGPU isn't available on Safari yet, but when it is it will be a paradigm shift ushering in a new era of distribution of software, one where you don't have to go through the platform owner's store as the only option available to you.