I can confirm this is true with my son (24), his GF, and most of their peers. Facebook interaction is limited to occasional sharing of photos with older relatives, usually via Instagram.
This is mostly true of my younger employees, who are a similar age as my son.
Definitely makes me wonder if Instagram got rid of the crosspost-to-facebook feature, how much more dead would Facebook appear? Most of the people around my age group (20-30s) are largely on Instagram and then some cross-post to Facebook for the "old people."
This is mostly true of my younger employees, who are a similar age as my son.