Facebook is what you make it.
If you want to post pictures of your food, FB can do that.
If you want to have conversations about serious topics, FB can do that too.
Me? I use it to keep in touch with a range of friends. Instead of writing a full email or letter, I can 'overhear' a snatch of conversation and briefly join in. Or I can glance at a photo and pass a comment. Or maybe someone's asking for advice about somewhere/thing and I happen to know a brief snippet that could help. It's a bit like mingling in a bar, except I don't have to buy drinks and I can walk away from any conversation where I am bored or boring.
And likewise, I can choose to do nothing and say nothing, and maybe not even bother checking in to see what's going on. I've turned off the notifications on my phone, so I'm not bothered by endless pings, and I use FB when I want to.
It suits me well. I've got back in touch with some friends who'd I'd lost contact with, and made some new acquaintances. Sure I've never met some people I talk to, but that's no different to this very forum and I'm fine with the concept of the 'internet friend'