Here me out, iMessage on any OS, wait, no, not just that, how about no hardware vendor is allowed to produce software that only runs on their hardware and for any given core function the hardware must prompt the end user with a competitive selection of capable apps to accomplish said function (to be downloaded and installed upon selection) instead of coming with a default option enabled. Let's get crazy and say that any hardware vendor must allow software they produce for their own hardware to be uninstalled and replaced by software of the end user's choosing.
I'm talking some "treating United States v. Microsoft" as legally binding precedent" shit.
(Side note: what's up with the bullshit where Apple makes an Android-native AppleTV app that will install on a phone fine but is blocked from running once it detects it's not an AndroidTV device? Apple acts like it would be an undue burden to make iMessage for Android (and pretends they didn't make the decision to not release an Android client with their hardware business in mind) but their Apple Music app somehow runs better on Android than it does on iOS...)