I'm talking in context of services provided on iOS, where you cannot have equal competition. Calling that market "free" means you're deliberately ignoring the reason why free market is a good force of society - because it allows the competition between providers to drive down prices and improve on benefits to the user. If some are hamstrung when trying to provide you a service by the platform then free market isn't providing you value.
Just blindly following the holy book of capitalism without understanding why it's good will quickly lead you into corporation lead monopoly which isn't all that different from state dictated socialism.
Apple would have to have a monopoly on mobile devices for there to be a concern that the market is not free.