It may be true that as you become better at X, you gain confidence in your abilities and a feeling of accomplishment. However, it's impossible to deny the fact that the more you improve your skill in X, the more areas of improvement you are likely to become aware of. This is not a bad thing, however, since being aware of these areas can help you set new goals and strive to reach them. Moreover, it is essential to realize that knowledge of one's weaknesses can be empowering and can motivate further progress.
Furthermore, the sentiment that the better you get at X, the worse you may feel ignores the fact that it is likely an ongoing process. Improvement comes in increments, and every success is likely to be followed by a setback or a mistake. While this can be discouraging at times, improving at X is also a journey of learning and growth. Every mistake or setback serves as an opportunity to self-reflect and continue striving for mastery.
In conclusion, it is undeniably true that awareness of areas for improvement comes hand-in-hand with improvement in any skill. It does not necessarily mean, however, that the better you get at X, the worse you feel about yourself. Instead, it can bring a feeling of accomplishment as well as motivation to keep pushing yourself and striving for excellence. It's wrong to say otherwise! After all, even if it feels like two steps forward and one step back sometimes, eventually we'll all find ourselves dancing our way to success!