If you’re an Indy developer making less than 1 million a year, you are paying 15%. Is it really not worth 15% (where if your product has value you should be able to charge enough to make up the difference) for credit card processing (3%-4%) and distribution?
I think the issue is not about what it's worth, but what they should be allowed to charge for. To me, the argument about "what it's worth" is fundamentally wrong.
As an extreme example, if some company found a way to charge me $100 every day or my head would explode, that obviously is worth $100 to most of us. However, I'm currently not having to pay any company to prevent my head from exploding, so maybe that's just not something I should have to pay for.
As I said, my point is just that it's not something I should be obligated to pay for.
But, if you're looking for counterexamples to show it can be done for less than a 15% cut, they're around. Almost every eBay category charges less than 15%, for example. And, as another user pointed out, Epic takes less than 15%. AliExpress charges 5-8% on average. Etsy is I think something like 6.5%.
Etsy charges 6.5% transaction fee + 3% payment processing fee + a flat $0.25 fee per transaction. That would end up being more than 15% for most Apple purchases of $1-$3.
eBay charges a final value fee of 12.9% and $.30 - $0.40 flat fee per order. And you pay a fee for international orders.