iMessage has been compatible with RCS for months now.
But then oops, turns out Google’s on wireless service doesn’t even support it. Maybe google didn’t think Apple would call their bluff?
That, plus other little slights like only buying high-quality aerial photos of upstate NY years after Microsoft did left me feeling that Google saw me as a non-person because I didn't live in the bay area, NYC, LA or DC.
You also sometimes have to enable in the settings for Android Messages (and have a supported carrier). iMessage also has an option to enable RCS but I believe its on by default in the newer versions of iOS
Even if it worked with 3rd party apps, at that point why not install something like Signal.