Young people aren't doing things without worrying about looking stupid, they just don't know that they look stupid. I say that as a former young person who was way more naive than I thought I was at the time. This is good and bad.

Also I think this point ignores that as people grow in their careers they often become more highly leveraged. I've moved from writing code to coaching others who write code. It is very normal for much of the "important" stuff to be done by relatively young people, but this understates the influence from more experienced people.