They are not asking for special treatment.
They are asking for the courts to curtail Apple's absolute power over how applications can be installed on an operating system designed for general computing.
That would be a game changer for the entire developer ecosystem.
Whether that's good or bad is another debate, but the industry-shifting impact it could have is undeniable.
Apple could easily make the case that the platform was never designed for general computing. It was never an open platform, and what Epic is asking is for the government to 'compel speech' from Apple in the form of changes to their product in order to make it one.
If you steal an candy bar, the government can "compel speech" in the form of forcing you to return the stolen property.
This is a great example of a thing that is not remotely 'compelled speech.' Here's the wiki article on the topic[1]. There's a pretty high bar for the government to create exceptions to the First Amendment.
A better example of compelled speech is the FBI trying to require Apple to write software that would give police a backdoor into any iPhone user's phone[2].
[1] https://en.wikipedia.org/wiki/Compelled_speech#United_States
[2] https://www.eff.org/deeplinks/2016/03/what-we-talk-about-whe...
This kind of thing didn't exist before because it was impossible to make people follow the rules, and it's pretty costly to maintain, given that Apple has to vet all the software, host all the content, and do that across hundreds of jurisdictions with various local rules.
Before Apple there was no way any of this could happen, Google followed suit only because it looked so profitable, and they could afford to bite the losses for as long as it took to prop up their smartphone.
So, yeah, it would shake the industry to the core, just not the way most of the people begging for it think it would.
It is called a built-in feature and iPhones were designed with it from the very start.
It was also marketed accordingly.