Although FB owns Whatsapp, messages are encrypted and deleted there, right? So your privacy is mantained, I think. Messenger of course is completely different and FB uses everything on Messenger to track you and your interests. FB is completely intrusive but I also think if we know how FB is keeping a shadow profile on each of us, we can play games with it, post links to data we dislike, not be very active .. I think enlightened users are not swayed by FB and are not really its target group.
I'd like to recommend this podcast, Goodbye Reality, a conversation between Erik Davis and Mark Pesce. Pretty in depth about FB and the way it seeks to capitalize users' attention completely. Also how it has colonized so much of the internet and cultural space.