Google Allo, Google Hangouts and Google Hangout will be discontinued. Google has not publicly revealed the reason behind the impending discontinuation. The head of the Allo developer team moved to Facebook effective January 2018, coincidentally the current version of Allo was released at that time period and never updated since. Google believes that multigroup video chatting has a lot of use in the Enterprise compared to the consumer space. The consumer version of Hangout available from Google Play using a regular Gmail account will also be retired.”]
Source: https://hackercombat.com/who-will-be-missing-google-allo-hangouts/