Google was criticized by privacy advocates for storing messages in a way that would allow the company access to them; this opened the door for law enforcement requests who would then gain access to a user's chat history on legal request as well.
Allo was first announced some 2.5 years go in conjunction with Google's video chat app Duo.
Whether Chat succeeds will depend on carriers, as Google can't just say "OK fam, we're all RCS now".
It surprises many observers that with such a large base of Android users that Google has, it has not been able to develop and grow a steady messaging platform like the iMessage that Apple could succeed in developing or the Facebook Messenger.
Rather than viewing Allo as the mistake and waste of time that many people saw it as, Google appears to view the service as a testing ground for features.
At the moment, Google seems to be pinning its hopes on its Messages app.
As we talked about earlier, Allo stopped getting attention from Google back in April as the team was pulled off of its development and put onto Android Messages.
The other report I referenced at the start of this involved Allo, Google's never-popular-because-it-had-major-flaws messaging app. While we don't know yet if the giant Internet company is working on a more performant instant messaging app, that would be the correct move, whatsoever. So it should come as no surprise that Google is looking to get rid of Allo, and it is being replaced by Android Messages, unsurprisingly.
In addition to live video and audio chats, Duo can record messages when a recipient is offline. Some users, including myself, did not really want to invest into another Google communication application that would meet the face of its predecessors eventually, probably. Though there is no date as to when Hangouts Chat and Hangouts Meet will be available to all, so that might be in 2020, or it might be a bit further down the road.
If you are using Allo, you need to find something new pretty quickly.