The platform is defended by Apple by pointing to the small-business jobs and revenue it creates.
The company cited a study by Analysis Group that found developers who earn under $1 million a year saw their revenue go up 113% over the course of two years. In the US, that number reached 118%, though it was lower in some countries.
The study commissioned by Apple found that the App Store supports 2.2 million jobs in the US and that more than 90 percent of developers are small businesses.
Apple cut its commission in half for developers who made less than $1 million in the previous year. Developers who enroll in the company's small-business program pay 15% less than Apple's 30% fee.
Tech giants are facing fines under new EU rules.
Big Tech companies often use small businesses as a talking point against critics and regulators. Meta Platforms Inc., the owner of Facebook, has used the tactic against Apple, saying that privacy restrictions make it more expensive for small businesses to reach their customers.
The App Store is under intense scrutiny from government officials in the US and Europe.