I just uninstalled the facebook app from my phone, and I don't use Messenger, although I still have to use Whatsapp (which is owned by Facebook) because that's what literally everybody uses.
"because that's what literally everybody uses." This exact same statement could be said about TheFacebook.com. How is using WhatsApp any different, if the goal is to disrupt Zuck's data collection?
I'd argue the purpose for most people leaving FB is to waste less time and privacy is generally a nice side effect but rarely a primary factor for the general population.