Enabling this like Ticketmaster enables selling tickets.

In ticketmaster's case I believe they give kickbacks and lucrative exclusive contracts with large venues, to squeeze smaller ones, maybe making whole tours use it but only kicking back to the biggest or select venues on the tour I think.

Apple sometimes does special deals and special rules with important providers, among many other tactics behind their moat. All single signons must also offer apple single sign-on, for instance, and they have even disabled access to customer accounts using their single sign-on for unrelated business disputes, though they walked it back in the big public example I'm aware of, the threat is there if you go against them in any way.

I could see Stripe doing something like this. They protect the consumer and come down hard on the merchants.

Imagine them, and maybe a few other processors, competing for this business. The fee would probably drop below 30%. To a large degree, this is the sort of arrangement credit card processors already have between their merchants and consumers and that rate is single digit percentages. Not hard to imagine Visa or MasterCard running a SaaS transaction service for a 5-10% cut.

Okay, all the app developers pull out of iOS because they're not actually useful, in fact they should be paying Apple!

How many people do you think would still buy iPhones if there are 0 apps on the app store? Lmaooo, it's almost like it's a co-operative relationship and Apple don't deserve a huge cut because it's the apps that sell their phones.