Maybe it's just my friend group, but absolutely everything is scheduled and planned through Facebook events. I basically don't visit, I use Social Fixer to trim down the news feed when I do, but Events is invaluable.

Yeah, I think it's just a matter of social circles. For me, events exist on Facebook, but plenty of people get invited off of Facebook, and the events are private so there's no discovery aspect you'd get in your news feed. I get told in person about most parties or events before seeing an invite on Facebook.

I do like and use events on Facebook, but I wish it was any other service at this point. It's all about the network effect though, it doesn't matter how many better options there are if no one has an account there.

It's used a surprising amount for academic discussion in my field, especially more informal stuff like which conferences to submit to or follow-ups to recent controversies. Basically the discussions that 10 years ago would've happened on a mailing list, or in the comments on a prominent person's blog. Some of that also happens on Twitter, but a somewhat different subset of discussions go there.