They have in a manner of speaking. The communication channel is still encrypted, they just run their surveillance algorithms directly on your device.
https://www.forbes.com/sites/kalevleetaru/2019/05/05/faceboo...
https://www.forbes.com/sites/kalevleetaru/2019/05/05/faceboo...
It's running in your device, you don't have to trust them if you have technical skill.
They might convince me if they open their client and server code, but even then they're yet another walled garden only interested in keeping their monopoly by building inferior products and using regularly capture to prevent any competition from doing the same thing they did to MySpace.