In a perfect world, there'd be a "pay with Apple Pay (€2,60)" button right next to the "pay with iDeal (€2,25)" button, just like on most web shops. If you prefer to use Apple's services, you can pay the extra costs for the 30% Apple tax and lose nothing you have now. Apple are the ones putting extra restrictions on app developers, I'm sure devs would love to have the easy Apple option available right next to the cheaper option!
To me, Apple's behaviour reads like they know they can't compete in an open market with their payment processor fees so they'll fight tooth and nail to keep any form of competition out. Their cut is simply unreasonable compared to any other payment provider, but of course they'll try to fight their billions in profits whenever they can. They go so far to force developers to increase their prices and even forbid them from showing the transaction costs in the checkout screen.