I'm not sure why it's super surprising. Facebook's data collection has never personally harmed me. I like Facebook because it helps me stay connected and tools like whatsapp/messenger are some of the best cross-platform messaging tools.
Yes, Facebook has downsides, but I've never experienced a privacy-related downside.
Someone should provide a link to an article that exposes some really nasty stuff about Facebook--I already know Facebook knows my address and my likes/dislikes and probably what sites I browse (since many sites use Facebook tracking), and it reads my messages, but in a way, I don't really care about those things because Whatsapp and FB Messenger are free.