[arghwhat]

When a service reaches a certain size, it is not just a small free service for its users. This is the point of gatekeeper regulations: Ensuring that services large enough to have significant impact on people are well-behaved and compatible.

The argument that iMessage is a service provided by Apple for Apple products and that they should be allowed to do whatever with their products is the same argument they've used to restrict App Store, force developers to use their payment systems and charge outrageous cuts of every payment a user might make through there.

iMessage plays quite a notable role in this, as a user whose friends use iMessage (more prevalent in parts of the U.S. I think) might feel unable to move away in order to be connected to their iMessage-using friends, in turn ensuring that they keep buying iPhones and paying Apple a 30% cut of all their app subscriptions from Duolingo to Disney+.