Learning the origin of our thoughts does not in itself make us feel better. Understanding the root cause of my insecurities does not help me if I continue to feel insecure. If I continue to think bad thoughts about myself, I will continue to feel bad. If we want to feel better, we must think better thoughts.
Sadly, even that is not enough. Not only do we have to think better thoughts, we must also believe those thoughts. Learning how to think and believe helpful thoughts about yourself, on purpose, is the basis of managing your mind, and the way to achieve this is through the practice of thought work.