The question is whether the law requires Apple to code their OS to make that easy for you. It’s up to the courts of course, but I’m skeptical there is a viable, consistent legal theory available to Epic under current law.
That's a strange one. In patching security holes, Apple are actively preventing people from jailbreaking their phones. And they should be. So that argument seems ... problematic. This kind of thing was never about making it easy to jailbreak your devices. Actually, it's kind of about the opposite: you should be able to own a device that runs code of your choosing and also have that device not be riddled with security vulnerabilities. (And, despite Apple's bizarre insistence to the contrary, this is very possible).