... and then the Wizard drops a fireball at level 5 that catches twice that many people and deals damage even if they save...
Broken is such a relative thing.
(Not aiming this at you FrogReaver, just comparatively, martial melee attacks tend to pale what's being done with spells).
On the rare occasion I've tracked damage, martial types do just as much damage as wizards, it's just more spread out. Other people have done things for streams like CR and found the same results. Fireball seems awesome, and it can be. Sometimes. Meanwhile fighters are the tortoise to the wizard's hare.