Then let the market decide if they're ready to pay 30% for that, when they can get <1% at larger competitors who are not even allowed on the platform. iOS is so ubiquitous at this point it should be treated by regulators as a platform, not as a product.

Sure and if they believed consumers value that, they wouldn't object to competing with alternative payment options.

... and competitors do the same for less than a tenth of that cost. The only thing that allows them to do so is complete control over the ecosystem to shut out all competition.

If that were the legitimate reason, then they could accomplish the same goal by requiring all in-app purchases to have the option of going through them, rather than exclusively going through them. Then people who cared enough to pay the 30% Apple tax could have that protection, and the rest of us could save a lot of money.

Paypal does the same thing and charges an order of magnitude less.

which I very much agree with.