I agree with your list! Except with your use of the word essential, because I was trying to draw attention to the fact that these jobs are highly reactive, whic

I agree with your list! Except with your use of the word essential, because I was trying to draw attention to the fact that these jobs are highly reactive, which I think is orthogonal to how essential they are to society (i.e. not "bull shit"). As a counter-example, I think everyone who is currently working to reduce environmentally-damaging emissions of industrial processes are essential to society, but if they all disappeared tomorrow it would have little immediate impact.