I'm a 54-yo techie. There seems to be far more people my age and older than I ever saw on reddit. Part of the reason I say that is so many mention their age when appropriate in context. There was an Ask Lemmy thread the other day where you almost had to state your age and I felt on the mid-younger end. Weird.
Also, there's so many joke and memes that I would think only Millennials or even back to GenX would get.
"As god as my witness, I thought turkey's could fly."
Loads of people will get that reference. And that aired in 1978!