30% is a reasonably cut for transactions that take place in your store, the main complaint I see about Apple and their store and the cut they take is that they want 30% of any money that goes through any of their devices at all, not just their app store. Relevant here, they are charging the 30% fee for people’s memberships to creators on the platform, a process that is wholly separate from Apple’s ecosystem unless the user is using apple pay to pay for it.