I hope Epic loses in a spectacular way.
At this point, if Apple is forced to allow third parties, I'll lose one of the best time savers I have in my life. Having switched all of my family and close relatives to Apple gives me the freedom of not having to provide almost any support. They are trained to use the platform (and its UI has been stable for years), and I can trust that they won't do anything too crazy just because [insert social network] or [crappy game in vogue] want to sideload a lot of bloatware and spyware on their phones.
When they had android phones, I would get regular phonecalls that went like this:
"My friend X has an app that does [irrelevant stupidity that requires full permissions], how can I do that?"
"You shouldn't, this will have access to all of your info"
"I don't care, just tell me how to do it"
Then 2 weeks later I'd get another call complaining of how full of ads everything is when they try to open a browser. I tried to disuade them by saying "Your phone can't do that", but that just meant that they ended up changing phones, because now they feel that their phone is inferior.
When they switched to iPhones, i can just tell them "Your phone doesn't do that", and they had no problem. They realized that bragging for 10 minutes was an idiotic thing to do anyway, and they felt great, because they still have a flagship phone, "it's an iPhone!".