Speaking truth is really important for your self-esteem as speaking truth makes you brave, reduces stress, and builds your character.
And Believe me, your character is tested in the most difficult phases of your life, and those with great characters are able to survive those difficult circumstances and grow out of them as stronger humans.
And these are the people who eventually get successful not just in a conventional sense but in the true sense, they leave a peaceful life without any guilts and regrets.