‘Fortnite’ Creator Says Apple Is Threatening to Curb Access to Software Tools - WSJ

The companies have defended their app stores’ policies, saying the 30% fee they both charge developers is justified because they provide services such as e-commerce security and user privacy, and that it is in line with what most other app marketplaces charge.

Yes, the 30% is in line with the other marketplaces because Apple set it first and everyone followed the leader.