The problem is that huge swaths of people can do those "most valuable" jobs, so they will chronically undercut each other to a stable salary point.
There is no conspiracy or scheme going on. Most people who set out to become a teacher or sewage plant worker are successful in doing so. Very few people who set out to be investment banker VP or real estate moguls succeed, but we hyper focus on those who do, ignoring (more likely unaware of) the graveyard of broke losers who didn't make it.
On the flip-side, if we had a way of finely grading, say, teachers, then the teachers in the top 1% percentile could likely demand extremely high paying salaries...because 99% of teachers would fail to make this grade.