Reminder: millions of people send SMS's and don't care one bit about encryption, and they only use WhatsApp because it's free to send messages, and pictures are supported.
Apple defaults to secure if iOS users are texting each other. Google has always done the opposite. I don’t think it’s a coincidence that Google is the one who’s business model depends on sucking up as much content as possible.
Why would anyone who cares about encryption have been using it for the almost decade up till now?