This is completely about the kind of splurge in app purchases that are terrible for consumers.
There are well known and detailed App Store rules about this stuff, if you want details just look it up. For example all those 2 factor authentication app fits this model where it’s meaningless to download the app without a subscription.
If you offer a multi platform "content" app on iOS then users should always have the option to create a subscription account directly on their iOS device. It's perfectly fine to create an account on a different platform and use it in the iOS app but this should neither be required, nor be directly advertised in the app.
Seriously, don't make random stuff up. Amazon and Netflix don't receive preferential treatment. If you want to make your own streaming app on iOS you can do that today as long as you follow the rules.