How is Apple keeping iMessage an Apple exclusive anticompetitive? That’s like saying Google needs to share their search algorithms because they’re “leveraging their position in the search engine market to shore up their restrictive products.”
In the end, Apple created a service that is massively popular and makes people want to use their products. The fact that US teenagers refuse to use one of their many competitors is hardly their fault. The rest of the world doesn’t give a shit about iMessage either.
Google search is available on apple devices though. Same with stuff like Gmail. Imagine if YouTube didn’t have an app for iOS and you had to use the browser. That would be worse for consumers, but Google could use it as a way to force people into Android. That’s what Apple is doing with iMessage and the whole phone ecosystem is worse because of it, whether you care or not.
You can read about it here: https://www.macrumors.com/2021/04/09/epic-apple-no-imessage-on-android/
Using a dominant market segment to reduce competition in another has always been an antitrust violation. A notable example is MS leveraging their Windows monopoly to force Internet Explorer on people.
