Totally agree. The virtue signaling in my feed is so insufferable that I stopped reading it years ago. It has basically become twitter with the vitriol replaced by fake positivity.
Yeah, I've always wondered the same. Maybe recruiters?
I do about 10 a day.
I've muted a ton of people I don't know at all because their rabid self-promotion or clickbait would keep showing up in my feed. But it is usually the same list of friends liking or sharing that content.