Most people think that being overconfident is a bad thing. A person can be overconfident or arrogant only for a short time. Sooner or later such people encounter an insurmountable obstacle. At such times, self-confidence disappears and is replaced by self-doubt.
In such a case, the person's progress slows down considerably and most likely he will never be able to be fully confident again. And this means he will not be able to overcome some barriers and become even better because he no longer believes in himself.
So don't underestimate or overestimate yourself and your strengths, then you can understand what you can improve in yourself and how to avoid making mistakes in the future.
But maybe some arrogant people just don't have enough confidence in themselves and that's why they give up so easily?