This has been an interesting thread to me, but I've realized something else.
I quit the only "popular" SM I was on (facebook) about three weeks ago. And up til that point I've noticed that the battery life on my '21 MacbookPro was steadily decreasing, from over a day (I charged it every night) to dying about 7 pm at night. Since I left facebook, my battery life is now about (right now, at ten pm, exactly) 33%! My actual daily "on-line" time hasn't changed (I'm getting more news/ewetubes to replace the FB time) so I'm thinking FB had a lot of "behind the scenes" activity going on, that isn't there anymore. FWIW.
Also, even though I tried to do everything to delete everything in my FB account, I still get the occasional (every two days or so) email (!) saying that a contact left a message, memory or whatnot. If I click on that, it takes me to my FB "Notifications" column, with all the inputs from my contacts but without any advertising; I read thru them and if I notice one post that has a huge number of responses from others, I click on that to see what's up, and again get no advertisements/clickbait.
I'm actually okay with this, so am going to leave things status quo. If there's something serious with one of my contacts I can email/call them directly. Just some FYI for anyone else thinking of deleting FB (I'm resigned to the fact that I can't delete all my info they have, unless I bomb their headquarters (and I'm too old for that anymore)).
Even when I was on FB I never installed their software, just used the browser version, read up on zucks history and you’d have to be out of your mind to install anything that came from him