Free apps that allow users to access paid subscription content aren't required to accept payments for the subscription through the app.
> Offer subscriptions through your own website or app rather than the app stores. This allows you to process payments directly and avoid the 30% fees. However, you'll need to provide your own payment processing and customer support.
https://www.quora.com/Is-it-possible-to-avoid-paying-a-30-co...
https://www.youtube.com/watch?v=WzQw3kEbEio
You can say it's easy, but if you try to make your app only take payments off platform you will fight with Apple for months.
Apple will gladly say they aren't preventing you from taking payment off platform and then make your life hell. They are big enough that this isn't some accident, this is 100% on purpose.
The whole LTT saga went on for nearly 2 years, you can watch all of it through their podcast: https://www.youtube.com/results?search_query=floatplane+appl... AND they had the benefit of having millions of viewer leading to them getting an active account manager... Imagine some random company.
Same with Floatplane, a streaming platform from LTT.
If you actually try to copy Spotify / Amazon you find out very quickly they have exclusive deals and their own account managers. You actually will not get approved for 5-6 months if you try to copy them, and even use their same exact UI and verbiage.
This is the part of the problem with Apple app store.