"Your Messages. We do not retain your messages in the ordinary course of providing our Services to you. Once your messages (including your chats, photos, videos, voice messages, files, and share location information) are delivered, they are deleted from our servers. Your messages are stored on your own device. If a message cannot be delivered immediately (for example, if you are offline), we may keep it on our servers for up to 30 days as we try to deliver it."
https://www.whatsapp.com/legal/?eea=1#privacy-policy-informa...
[1] https://www.washingtonpost.com/business/economy/whatsapp-fou...
https://techcrunch.com/2018/09/27/yes-facebook-is-using-your...
And also: it doesn't matter whether end users care about encryption or not, it still benefits them, this is exactly why end-to-end encryption is a very good default.
[0] http://gs.statcounter.com/os-market-share/mobile/united-stat...
[1] http://gs.statcounter.com/os-market-share/mobile/worldwide
I'm guessing the only thing that comes close to texting in terms of marketshare is iMessage. And that's simply because it is on every iOS device AND enabled by default.
I'm from the US but I've lived abroad the last four years. I'm still surprised so many people "back home" continue to use SMS texting. Everyone I know around the world uses WhatsApp. Literally, in every single continent I know and chat with people on WhatsApp.
Only Americans still use SMS from what I've seen. I just don't get it.