> Somewhat relatedly Apple really missed an opportunity with iMessage. Had they timed it right they could have had a dominant cross platform chat.
Google also had the opportunity to do this. Around the same time iMessage launched, Google made Hangouts the default SMS app on Android with a similar capability to upgrade to Internet-based messaging when all parties to a conversation had it. Hangouts was cross-platform. Rumor has it carriers whined and Google caved.
I'm kind of glad Google doesn't have a dominant messaging service, but it's only true due to their own lack of commitment.