This is just three big corporations fighting over their respective slices of the pie, if you think any of this is being said or done for your benefit I’m sure Epic has a plentiful supply of really tasty Koolaid for you. But no pie, sorry.
Apple’s rules prevent vendors from linking to external service account setup/management. You cannot even mention the existence thereof, let alone link to it or advertise the options provided therein. Consumers are explicitly kept in the dark about any method other than payment through the App Store.
That’s the stunning uppercut. The size of Apple’s fee is merely a follow-up kick to the nads.
This is why service providers, from Hey.com to Netflix, have a special irritation for the App Store rules, and since this rule directly distorts markets by affecting consumer choice is why so many competition regulators have a file open about it.
If Microsoft was playing hardball with Rockstar over the next version of GTA, as an example, Sony would be falling over themselves rushing to get it as a PlayStation exclusive. The console market and app market just aren't comparable.
I have no idea why you'd want to, but you can... UWP apps run just fine on Xbox and can be sold via the store - they just don't get access to the "exclusive" partition of the system (which you need to access certain system resources, such as > 2GB RAM). Sideloading prebuilt UWP apps is also possible. The exclusive partition is a different situation entirely - you need to be an approved developer to even access the SDKs.
I'd say there's a difference between what Xbox (and Playstation, and Nintendo) does compared to Apple by virtue of the consoles not being "open" development platforms (Xbox UWP aside). Anyone can grab the iOS SDK and start making apps, but only registered developers can do so on game consoles. Whether that's justified I don't know, I honestly haven't put enough thought into it. And whether courts would see that as a reason I definitely don't know.
Full disclosure, I work for Microsoft.
Google basically says, "we have a store. Sell through us and we take a cut. Or sell directly, or through some other store, and we'll warn users that we haven't vetted that stuff for security etc."