1.) web view/touch/audio streaming app - 10%
2.) accelerated web view/SDvideo app - 15%
3.) HDvideo H.264 app - 20%
4.) 3D Graphics/ARKit SDK app - 30%
3D and ARKit which are pushing the boundaries of the silicon probably do have associated R&D costs as well as silicon COGS costs that perhaps do need to be recouped in a manner similar to gaming console SW licensing agreements (i.e. Xbox, PS, Nintendo royalty payments).
In the court of public opinion it would also minimize the effectiveness of "think of the solo iOS dev" type scenarios that the big guys such as Epic, etc. like to hide behind.