FB: If we're not allowed to track you across the web, we'll use your data captured via our properties to make more money from you via targetted advertising.
fun fact: they also collect data from apps they don't own but which use Facebook SDK. eg. Opera, Duolingo, Kayak and tons of others. So deleting Facebook app and Facebook account doesn't do much as you think it's does.
Host list blocking only works as long as the apps use your host list. Very soon, every app which has something to hide will use DoT to the DoT servers of its own company to look up every host name.
