It's no secret that people like working with nice people.
At the end of the day, business isn't B2B or B2C - it's P2P, or person to person.
Ego has no place in the workplace, regardless of how good you might be.
Imagine working with that one guy we all know. You know, the one who always has to brag or show off all of the time? He might be good at what he does, but he will get old real quick. It's pretty apparent that he doesn't know how to be vulnerable or relate to others.
That's why I try to treat my professional relationships the same way I treat those in my personal life - with respect and honesty.
After all, life is too short to work with people who are assholes.