Then if you don’t want to pay the Apple tax you can subscribe directly. This incentivizes Apple to keep the fees low.
At some point, you have to just admit that as a business you have certain costs that you have to pay to operate. This mentality, that business costs must be borne by customers, is what's leading to all these ridiculous hidden fees and charges at other businesses.
There are many places that do not even accept AmEx specifically because of their fees. Charging more based on card use has always been a thing until the card companies used their cartel like persuasion to not allow that. However, I'm starting to see stores offer different prices for cash/debit than credit. I thought I remembered this being made allowed again, but it's early still.
You as a user feel like you should be able to buy whatever whenever with whatever mode of payment. That's very convenient for you even though you're the one that has decided to use that particular mode of payment even though you know your mode of payment is an absolute pain in the arse for the merchant. Not having you as a customer is a perfectly valid point of view from the merchant.
It also creates perverse incentives for cards to pass part of the merchant fees back to the consumer as rewards or even cash. Here in the US, 2-3% cash back is typical, driving consumers to prefer credit over other payment methods.
Meanwhile, merchants are forced to bake the fees into the retail price, causing the paradox that those who pay upfront end up spending more for the same goods.
Alternatively, you could take Apple's example and charge people an arbitrary amount for the privilege of accessing your business and leave the certainty of certain costs for the shmucks.
I 100% believe this should be the case. It's unfair to merchants to take away an arbitrary percentage of their profits depending on which card you want to use.