Society isn't really good at knowing what it requires. And sometimes it's better to be cautious. Also capitalism breaks down in certain markets, one of which is the "job market".
Any market that involves a lot of players and little oversight will get manipulated like crazy, including the job market. Employers try to counter that, but in the end the people that are best at getting hired for a job get that job, not the people that are best at doing that job. How could it not be?
And that includes the jobs of the people that do the hiring. So it's a market that's rife with inefficiencies.