Another anecdata, but our kid's babysitter (also 16) doesn't have a Facebook account, and neither does her twin sister. They both have IG and Snap though. She said the same thing: "Facebook is for old people".

Also my 20 year old cousin didn't have a FB account until he went to college and was forced to get one to join some local FB groups. But he only uses it for that. Otherwise he's on IG and Snap.