I suspect if the UI offered customers to pay now using Apple's thing, or have a button to get 30% off by going to some more convoluted flow, a lot of people would choose the rebate.
I think at the point they're making the transaction, they're already locked in. It's not like someone is going to buy a new phone and replace all their apps when they're purchasing an Uber subscription.
Plus, I think another commenter pointed out that the end user is still getting the same price on Android - I don't know if that's because Apple mandates something or a business decision on the company's side?
Developers want less
Customer don’t care, and want what Apple is selling.
Developers feel it’s not fair because they think they are losing money but customers seem happy to pay for Apple’s premium service.