I must be a real outlier on Facebook. My friends talk about bad things in their lives as well as good. We give tons of emotional support for the bad times and congratulations for the good, the latter being all the more meaningful because we know the struggles people have gone through to get them.
I have a core of friends on FB I've known for 20-30 years. Friends I had to leave behind when I moved from Rochester NY to Madison WI in the winter of 2010.
And I've developed good, supportive FB friendships as well. We share bad times as well as good. We have mostly shared political viewpoints and support each other through bad news and good. We learn from one another.
My group seems to be the best that social media is intended to be. Which is particularly important to me because I am disabled by multiple conditions and have been without a car for 2 years (thanks to stroke), and it's very difficult for me to get away from home.
BTW I haven't heard the people can add you and you have to add them back. I still have to give people permission to add me, and there's no "adding back" because if I accept a connection it goes both ways. But there is no HAVE TO about any of that. You can still limit the number of people who can read and comment on your posts. I have "friends" whose posts I never see and who never see mine.
I'm not promoting FB here, just pointing out that what you get out of FB depends a lot on what you put into it, and the care you take with friends who can read and comment on your posts.