Google had a chat app, then they created another chat app called "hangouts" and forced everyone to switch to it, and now they're doing it again. I don't underst

Google had a chat app, then they created another chat app called "hangouts" and forced everyone to switch to it, and now they're doing it again. I don't understand the logic here. It's still just... chat. If this is a good idea, then wouldn't it also be a good idea to create "google mailbox" and force everyone to switch to it from gmail? I mean it's the same level of pointlessness, right?