It is not about profitability at all. It is about offering mandatory services at extraordinary prices. App distribution, content distribution, payment and accounting services are all nice if you want or need them. Like the other guy in the thread who said he's thankful for all the payment stuff being handled for him for 15%.I don’t see what is so controversial about App Store profitability.
But companies like Epic and Spotify do not need these services. And therefore they should be allowed to opt out. Apple could then offer different, more tailored, more attractive packages. Like fully integrated payment for 5%. Which would be more in line with industry standard rates. Also, the same built-in mechanism could be used to pay for physical products too (which you cannot do now), probably making Apple even more money overall than now.
The result: Companies paying for services because they find them wothwile due to excellent usability and app integration with industry-leading, high conversion rates. Instead of having to pay mandatory fees for something they do not want.