Your missing a key point in all this Epic for example want their own store and not to put their app on the Apple or Google store. When Epic wanted you to sidled on android, they didn't put their app on the google store. This might not seem a big deal but once epic has a store everyone wants their own store. Who will police these stores? When a dodgy store uploads a dodgy app and peoples iPhones and Android phones get hacked or data get gets stolen, these people wont be blaming the App Store they got the app they will be blaming Apple and Google. The headlines will read iOS /Android is hack or iOS / Android leaks users data
Honestly, I'm not missing any of that.
Let's talk about policing the store first. Apple has convinced everyone that they check all apps, but this simply can't be true. I'm sure they look for obvious malware, etc. I'm not suggesting they do nothing. However, given the volume of submissions to the App Store and the length of time it would take to TRULY pick apart an app's code and make sure it wasn't doing anything dodgy, it's simply unreasonable to think they do a thorough review. Plenty of questionable apps have made it through review (clipboard snooping anyone?).
Personally I don't need a nanny to vet my software purchases. I've been buying software for nearly 40 years without needing a big corporation to hold my hand. My big concern, as I've noted previously, is control. This is a very dangerous slippery slope and I see Apple fans lining up to give away their freedom because they love Apple and/or believe that Apple will protect them.
I personally believe that if Apple's App Store survives this current assault, each of the major platforms will move towards a single App Store model. It wouldn't remain unique to Apple. In that world, a handful of massive corporations literally control the flow of all information. Do you want to live in that world? It's a scary thought. Just because things are good now doesn't mean they'll be good ten years from now.
In another thread
@canesalato brought up the possibility that a developer might release an app that is critical of China. China threatens Apple. Apple pulls the app. This is a very real possibility. Now imagine if the only way to install apps on your phone or tablet or PC is via one of several app stores. Each of these massive corporations has a vested interest in not upsetting China, not too much anyway. So they all pull the app. This is not far fetched.
As for Epic, sure they want their own App Store. I would too. Everyone wants an App Store these days. I have no problem with multiple App Stores. That's what competition is all about. It's funny when I read posts from people on here extolling the virtues of competition when it comes to hardware, yet those same people defend Apple's iOS App Store monopoly. There's a lot of cognitive dissonance among hardcore Apple fans.
Apple can still offer an App Store as a service. Many, if not most, users would probably choose to only purchase from the App Store. This is how things are on the Mac today (but probably not for much longer) and it works very well. If you're only downloading from the App Store, you're just as safe as you are today. Nothing changes for you. If you want to install other App Stores that offer apps outside of Apple's App Store guidelines, you may do so. Is that really such a bad thing?
Take adult content, for example. Why can't I develop an X-rated game for iOS? What right does Apple have to tell me what type of app I can and cannot develop? Where are all of the champions of the free market and competition now? Like I said, hardcore cognitive dissonance. Apple has every right to not want to carry my app in their store, but to wholesale deny me access to the platform because they are trying to force their morality on everyone, that is highly problematic to me.
Edit: Imagine if BMW prevented you from driving to certain parts of town because they deemed those areas unsafe or immoral or they simply didn't like the idea of their brand being associated with those places. Would you support that?
I don't really care about who gets 30%...or 20%...or 50%...or whatever. I care about freedom and keeping platforms as open as possible. Perhaps I've just read too much sci-fi, but what Apple is doing today gives me the creeps. They are not my mom and dad. I don't need them to protect me from myself or do some government's bidding. On August 1, they removed nearly 30,000 apps from the Chinese App Store. Poof. Gone. Because some authoritarian government told them to do it - or else. No one should be celebrating this business model. Epic might be unethical and shady, and they might be doing this for the wrong reasons, but their cause is worthy.