The less honest you are, the less likely you are to know and fulfill your potential. To the extent that you are dishonest, you will have an incorrect idea of your potential self-worth. Dishonesty will limit your awareness of how good you could actually be and how to become that way. In the state of ignorance imposed by dishonesty, you do not know how good you could be, or what that would be worth to yourself and those around you.
While you live in self-delusion, you absolutely limit significant growth. You cannot turn away from honesty without turning away from the good you would otherwise do. Truth builds on itself. A building cannot be built taller than the limits of the strength of the foundation. While you hold to incorrect ideas about yourself, you will be limited in how much you can grow as a person. The widespread costs of dishonesty will keep you from recognizing or having the power to leverage opportunities for improvement. The truth will show you your strengths and weaknesses. Reconciliation to honesty is the only way you can live up to who you are and become who you could be.