FB and Instagram as a whole are a cancer on society.
In what way?
It is not just individuals who use Facebook as a means of group communication. The organization for whom I am the board chair has thousands of members around the state and some who are scattered nationally and internationally. Our audience is largely made up of retired or soon to be retired seniors. We provide information, not just about our organization but also information that is pertinent to all folks particularly seniors.
Another association I belong to has approximately 19,000 members all over Oregon and parts of the neighboring states. Besides having had a webpage for decades, they also communicate via Facebook.
Facebook is not just about those folks that feel the need to announce every boring detail of their lives, like where they are at the moment or what they are eating for dinner. Most people using Facebook aren't on it for the sole purpose of amassing a huge number of "friends". I have a Facebook page. One feature I like is that I get reminders when folk's birthdays occur which allows me to send them a greeting, which I'd otherwise likely forget to do.