Google has struggled to compete with some of the other chat apps out there. Hangouts has not really taken off and they are retiring Hangouts on air in favour of Youtube Live. They have just announced a new app called Duo that uses phone numbers as unique ID rather than a Google account. They also announced another app called Allo a few months ago. This could confuse users. We end up needing multiple chat apps to talk to different friends. I already have at least four on my phone. There have been attempts to create universal standards (e.g. Jabber/XMPP), but each company wants to push their own technology.
