Others have touched on this, but ultimately the most vital trait a person can possess is perseverance and a bias for action. I would gladly work with a mediocre person who works relentlessly at improving their skills and figuring out solutions. I don't enjoy working with "gifted" people who have plenty of ideas and few actions to show for it. Intelligence can make you risk averse, and you're useless if you're too afraid to take any action.