As Seirdy notes:
It just keeps getting more relevant. WhatsApp, GitHub, Twitter, Reddit…each disaster worse than the last. The companies in charge know that the users will just take it after having their autonomy taken first.
It used your existing phone number as your identifier
Wait, people think of that as an advantage? For me, that has always been the reason I have refused to use it. It’s also why I never even tried Google’s Allo despite being a big fan. A chat application that isn’t using the phone network shouldn’t be tied to your phone number. It makes cross-platform support extremely awkward, and that’s noticeable in how poor What’s App still is for cross-platform use.