At one point in my career I just wanted to be able to do my job. Then I got to the point I wanted to be able to do my peers jobs.
When I became a supervisor I thought I should be able to do all of my workers jobs to be effective.
When I got to middle management I had the epiphany I should be able to do my bosses job if I was going to be successful.
When finally I got to be a director at a big company all I really needed was for everybody else to do their job.