According to EU this is a distinction without meaning and not protected by copyright.Calling iOS APIs is using iOS code.
They aren't taking a cut on use of the API's, the API's are free, the code behind the API's is proprietary and subject to a license.
Epic and Unity's cut is based on revenue, why can't Apple do the same?
The difference is epics code is shipped physically in the game.
iOS apps aren’t shipped with any iOS code.
APIs) and other functional characteristics of computer software are not eligible for copyright protection. Users have the right to examine computer software in order to clone its functionality—and vendors cannot override these user rights with a license agreement,
The purchaser of a software licence has the right to observe, study, or test the functioning of that software in order to determine the ideas and principles which underlie any element of the program. Any contractual provisions contrary to that right are null and void," the court ruled
Articles 1(2) and 6 of Directive 91/250 are to be interpreted as meaning that it is not regarded as an act subject to authorisation for a licensee to reproduce a code or to translate the form of the code of a data file format so as to be able to write, in his own computer program, a source code which reads and writes that file format, provided that that act is absolutely indispensable for the purposes of obtaining the information necessary to achieve interoperability between the elements of different programs.
Apples cut can’t be for providing no service