Comment by Zak
5 hours ago
Google tried the same thing Apple did long before RCS when it made Hangouts the default SMS app for Android. Conversations could be upgraded from SMS to Google's internet-based chat protocol if the other person had an account; it was even available for iPhones, but it couldn't be an SMS client.
Carriers didn't like it and Google caved.
Lets be honest, Hangouts (which of the three versions) was a crappy chat app that they wanted to boost the usage of. It wasn't intended to be a functional SMS replacement.
As a former regular user, I don't remember it being notably worse than any of the other options. It was definitely preferable to SMS.
Maybe there was some glaring flaw I'm not remembering, but Google certainly had the resources to make it more competitive if they'd wanted to.