As for Facebook it is best just to quit. I don't even use Facebook to keep in touch with friends anymore. The value in Facebook is some of the groups. Local neighborhood groups seem to be the best source of information or things happening around your area if you care to know about it. Also different hobbies/interests have local FB groups that are the most active place for discussion with far more users than a small subreddit or dying forum community.
Perhaps I am old but I don't know a single person that uses Whatsapp or Signal. Everyone just uses old fashioned SMS or iMessage if they have iPhones.