> When Apple controlled the payment system, Apple could be sued in your home country.

Have any App Store consumers sued Apple? And were they successful?

Apple does refuse App Store refunds all the time. Apple also closes consumer Apple accounts all the time, for some reason or no reason, often refusing to tell the consumer the reason, alleging some kind of fraud, in which case the consumer loses everything they've ever purchased. One of the reasons, though, is consumers doing a chargeback on their credit card, which Apple hates and punishes severely.