He's fighting to tear down walls so his role as a gatekeeper is more valuable. The Epic v. Apple suit explicitly mentions that, without Apple's alleged anticom

He's fighting to tear down walls so his role as a gatekeeper is more valuable. The Epic v. Apple suit explicitly mentions that, without Apple's alleged anticompetitive behavior, Epic would build a version of their store for iOS, and it's not a huge leap to think that Epic would roll out a version of their free games program on it to drive traffic.