What is worrying about FB is that the are fixing some of the advertising issues in time for the 2020 US elections, i have seen nothing about them doing the same in time for a UK general election (granted a possible early one) or even a re-run of the EU referendum. Both of which could be at real risk of being targeted.
As I have to use facebook to keep in touch with thelocal football team I have now installed a add on for Mozilla firefox (works with v57+) that creates a container and isolates facebook from the rest of the browser.
If I log out, and then go to the cookies page in privacy the cookies are still shown however, I delete them anyway, they should be isolated. There are some limts to this don't expect to click like on external sites for example or login using facebook but at least it offers some protection.
Still won't make me use facebook more than really needed. I am guessing this is one way round having to #deletefacebook of course is the preferred option.