on text IM, google did an old microsoft bait and switch. Everyone moves to gtalk, it is open XMPP, except that it is not anymore. sorry.

then came video and skype got everyone back to square one. but they were more worried about being bought by microsoft so they lost the mobile integration with phone numbers, and a bunch of others and made the "facebook deal" with their users. give us access to your phone number and contact list and we cross that. privacy for convenience. And everyone loved.