You are conveniently forgetting that this was a direct response to the Epic Games lawsuit, as to not appear too anti competetive:

https://www.cnet.com/tech/mobile/apple-lowers-app-store-tax-...

Apple only makes concessions when it is under legislative pressure.

15% can still be too much. Alternative music, book, etc stores often have high IP payments that make the business case impossible because 15% is more than the profit margin. And apple doesn't have that 15% for it's music and book store. It's the definition of monopoly privilege.