I find Google's choice to make Allo/Duo bizarre. Whenever you start a new IM system, you're starting from zero users, so the network effect is working against you
. And, to make matters worse, Google's new system doesn't work on devices that don't have a phone number (!), and has fewer features than their existing IM system (Hangouts) that does voice and video calls all in one app, already has a user base and works on a PC/Mac/tablet.
This makes me seriously question the management decisions at Google, and I suspect that these new apps won't ever challenge Facebook Messenger or the other "big" IM/voice/video systems (e.g. Skype, Snapchat, etc). I suspect they won't even exceed their existing Hangouts user base.