Why do you think older people are more foolish than younger people?
This is so patronising! I'm wouldn't dream of telling my parents what to read or not read.
Facebook is bad for everyone.
There is a documented age bias in the sharing of fake news [1][2].
"Foolish" is the wrong word. "Unaccustomed to modern social media" fits the bill better.
[1] https://advances.sciencemag.org/content/5/1/eaau4586
[2] https://www.nytimes.com/2019/01/10/us/politics/facebook-fake...
Because everything decays with age and its no more insulting to imply that mental capabilities have fallen than it is to imply physical capabilities have fallen especially in a rapid changing environment with tons of unfamiliar traps?
Mainstream media of facebook, news, or generic entertainment is mostly poop for everyone's mental health. I don't see any reason why that means we can't acknowledge people get slower as they get older.