Earlier quoted context omitted.
Spam killed forums. Facebook took since it wasn't plagued with spam.
Facebook content is now such low-quality that it might as well be spam (my opinion). Also, pointless, toxic conversations. It seems to bring out the worst in people. I know some people like it for keeping in touch. I refuse to use it anymore, not worth it for me.
No one posts actual quality content because stuff I want to read doesn't have a general appeal, its specialized to the things I am interested in. Facebook only allows for general appeal stuff so you end up with memes that everyone can understand.