In reality FB events are extensively used by ages 16-30 as well for bigger group gatherings, such as going on holiday, going for a weekend somewhere, or something like that.
Your anecdote look like something an older person would charicaturize about youth and elderly.
I don't understand why you'd use FB events for "going on holiday, going for a weekend somewhere." Those things would entail a smaller, tighter knit group with much more communication and planning. Group chat seems like a better fit.
IMO, FB events are really only suitable for things like parties, with an large invite/smaller rsvp dynamic, with mostly broadcast messages from the host.
Yes groupchat is better when it's less than say, 8 people.
FB events are suitable for lots of things, I woulnd't say it in such a reductionary manner like "only parties".
The 30+ crowd appears to believe that FaceBook is the most logical way to organize events - you can check in on your own schedule, without feeling pressured into immediately responding to someone poking you about joining up. Today's youth has no problem being expected to respond within minutes - or in the worst case, a couple of hours - to an inquiry made via SMS or Snapchat.
ie: Older person: "I may have some free time this weekend, maybe I'll check FaceBook tomorrow to see if anyone is planning something"; vs. younger generation: "Someone snapped our group telling us to come out with them Saturday, I'll decide in the next 5 minutes whether I'm in or out".