I've been a long time fan of Proton. Love what they're doing and their services, but I'm also in the e-commerce world. I find all these complaints of Apple taking a piece of the pie so interesting.
Anyone sell on Amazon or eBay? What do Amazon or eBay do? They take a piece of the pie. If you develop a game for PS or the Switch, Nintendo or Sony takes a piece of the pie. This is the same business model that SO many companies employ, and yet people like to single out Apple (or Google) for that matter for trying to take a cut. Apple has developed a platform that has traffic and a means of selling a product (in this case an app). If you want to play in their playground, you have to pay for that. Yes, I recognize it's a separate service beyond on app, but they are choosing to be on that platform to distribute.
Why doesn't anyone get mad at Amazon for taking 15%+ of my selling price for an item I've sold on Amazon? It's the same thing. It might be a one-time sale on Amazon, but if that customer keeps coming back and buying the same thing from me time and time again on Amazon, should Amazon not take their 15% cut?