You make several excellent point, Grant!
Yes; whilst some people will be able to see how some other people’s jobs don’t contribute much to society, many people will be reluctant to question the social worth of their own job. And if someone secretly knows their own job doesn’t contribute much, they may be offended the topic was ever brought up.
But, ultimately, we ought to recognise the problem so that we can be in a better position to deal with it. People may be able to feel much happier and more fulfilled if they can be confident their work is making a positive contribution to society.