Says a lot about our world that to be successful with a 'friend-based app' you really need to dark pattern your way into hijacking a contact list and robo-inviting all the people who are totally not a person's friends.
Even worse is an article from a major newspaper having "mixed feelings" about the feature.
If you paid attention, every single successful social app got so successful because of dark patterns that could be summarized as: spamming you and your contacts.
Snapchat. They even add contacts after you didn’t add contacts, no idea how they manage that exactly..