They know more about some things and less about others.
But, usually young people don't know as much more than their elders than they think they do when they are young. This knowledge comes slowly to us all.
Elders might know more, but I think a high proportion of that gets outdated.
I'll ask you this, in the quest for knowledge, would you rather know a small amount, that is completely right, or a large amount, some of which may be false?
I know which I'd rather.