It is quite ironic how people who believes in the benefits of being coached are usually bosses of their own. And people who does not believe in coaching always remain employees.
Roger Federer has a coach. Manny Pacquiao has a coach - Freedie Roach. Chris Rado has a coach/guru - Sadhguru. Richard Gere has a teacher/guru/coach is - Dalai Lama.
If you are serious enough about your career, you need a coach too.