The history of Google with instant messaging on mobile platforms has always been somewhat erratic. At the time it failed to take the opportunity to have its Talk application installed on all the Android that were sold to dominate the market since then it has been changing course without being able to prevail despite the advantages that counts.
Without going further, a dominant position in the sale of operating systems served to Microsoft to impose its web browser and that had to intervene the authorities to foment the competition in that scope. But Google did not achieve the same with Android, much less. The WhatsApp, Facebook Messenger, Line, Telegram and a long etcetera have eaten the ground to apps like Hangouts. And we are facing the penultimate attempt to lead this market, perhaps somewhat late.