I have a lot of friends who live abroad and FB is an easy (if superficial) way to keep in touch with them. I love seeing the occasional photo of their kids or days out or whatever I'm not a stalker, honest.
Some of my friends have the same interests as me so if I see a news item or post I think they'd like, I can share it with them.
There are some good local pages so I hear about local initiatives and events.
Those are the things I use Facebook for.
There are negatives too, of course.
Facebook often puts 'Suggested Posts' into my newsfeed. This is basically advertising.
Another problem is that the things your friends choose to share may not be things you have any interest in. For example, one of my friends was always posting really long, boring 'inspirational' posts. I'm not talking about a nice picture of a sunset with a brief inspirational quote. She would go on an on with very detailed accounts of her philosophy on life. After a lot of eye rolling on my part, I blocked her. Once in a blue moon I have a quick glance at her page to see what she's up to.
For some reason a lot of my friends share cute animal pictures or videos. Obviously there's nothing wrong with this and it's not offensive or anything. Just gets tedious after a million photos while.
You quickly learn to filter the news stories as you scroll through your news feed. I ignore the posts I've no interest in and focus on the ones that I find interesting.