Over confidence with skills really do lead to success most of the times cause confidence gives them guts to do gamble like win all or lose all. And with enough skills win all is an easy feat.
But honestly over confidence leads you to having enemies.
Most people seems to get infuriate when someone acts confident. They seem to mistake it for arrogance.
Arrogance is when people exaggerate their own abilities and show that they're more important than most.
Confidence is when people believe in their own abilities.