If you are the type of person that needs to be the smartest one in the room in order to maintain your self-esteem, you likely hire people that are less qualified than you. When everyone around you is less qualified to do their job, they have no other recourse than to fall back on your vast depth of knowledge and experience to survive. You remain the smartest person in the room by default because everyone else around you is incompetent compared to you.
And while everyone else in the organization sees you as indispensable, you have created a domino effect by setting the standard. The people you hire then hire people that are less competent than they are too, and the dumbing down of your part of the organization is well on its way to 100%.
I’m watching the fallout of an organization that normally does not hire like this and looks for people that are smarter and bring new talents to the organization. However, one senior leader is very insecure and staffs her department with people that don’t meet minimum job responsibilities, and must lean on her to solve work challenges. This makes her become indispensable because her team really does need her. Where it shows up most often as a problem is when she is on vacation or out of the office. Everything gets backed up waiting for her return.
I forget who said it first, but I have always agreed with the statement that “if I am the smartest person in the room, I need to add more people to the room.” I have always hired people with more expertise than me so my department not only survives in my absence, but we continually grow. While the direction may change with a new leader that replaces me after I leave, the team still functions because no single person was dependent on me for wisdom.
As a leader, if you hire someone that is totally incompetent for a job, you send a single that no one needs to be qualified to work for you and/or get promoted. Your managers will also mimic you and hire less than qualified people to remain looking indispensable themselves. Before long, the only person that can do their job is the one leader at the top; so what happens when they quit?