I just really can't understand the end-goal for Sweeney, here.
They want to be on Apple's and Google's storefronts, accessing hundreds of millions of potential users, making tens of millions of dollars in yearly revenue on the platform, but using external payment services to avoid paying a single penny apart from the $99/year (or $25 lifetime, in Google's case) developer fee?
Like, I agree that developers should not be locked in to using Apple's or Google's payment system and that there should be alternatives, but arguing that you should not pay any fee to the store owner is frankly nuts (and also hypocritical, since the Epic Games Store does charge a percentage of revenue for games sold there, regardless of where that revenue comes from, except in very specific circumstances).
Apple's store fee should be lower - 30% is borderline theft - and it makes sense that they allow external payment providers, but they should be allowed to take a cut - albeit smaller, of course - from those payments as well.