The Worst

Izuku's parents had cool quirks. His mother has a rather weak Telekinesis, but it was useful for a number of tasks. His father can breathe fire. He could have been a popular hero if he'd wanted to, but he'd never aimed for it.

Izuku got potentially the worst combination of those powers. Smoke Manipulation. A terrible power for a hero wannabe.

Especially when your already arrogant underclassman got a cool quirk like Explosion.