As I predicted when Allo was launched, if the app has no cross platform service + SMS users will not use it!!!
That sad thing is that Google invested a lot of money and time developing a smart chat system. But, we didn’t use it! Or maybe Google thought we’d love it.. Same as Google Glass.. Lol!
When is Google Duo dead? Or Google Lense? Or Google Now? Wait, what??
Google Now hasn’t worked properly since Nov. 2017. Sorry..
http://google.com/newsstand/s/CBIwgqaHnjg//cdn.embedly.com/widgets/platform.js
John Holme Blogg 
Sad as Allo is my chat app of choice amongst family, friends and coworkers. I’d reckon 70% of all my messages; sent and received, are on the platform. Facebook Messenger included.
Having said that, Allo is not without flaws. It’s not always a smooth ride, but it’s way better for image sharing than Hangouts and even Messenger and Snapchat. Unless you need to play with tacky filters and other gimmicks.
LikerLiker
Same here, the vast majority of messages I send are in Allo.
LikerLiker