Why? My job is extremely easy with a great team and manager. I could get more, but I'd have to work in a high stress environment, and life is too short for that shit.
I think the grandparent was implying all other things being equal. If the highest bidder requires that you work in significally different and more difficult conditions, then it's not really comparable.
Value comes in many forms. OP message shouldn't imply that money alone is the only variable in the equation of "am I compensated fairly".