Look at Raistlin from Dragonlance, or even the "colored" wizards from Middle Earth who basically truly are demigods. I could probably also add Elric (doomed though he may be, and servitor of the Gods rather than a competitor). Heck, what about Voldemort? Though he may not be a God, he (and Dumbledore) was the most powerful person on the planet? In the Conan books, sorcerors are rare, but usually the most powerful person in their kingdom that even the Kings leave alone or are puppets to them (and Conan seems to be the only person able to kill them who is not also a sorceror). I'm not even an avid Fantasy reader, so I wouldn't be surprised if there are others.Is it?
The core fantasy of the D&D Wizard to me is "I'm a studious caster, looking for old lore and spells to increase my power and contribution to the group."
Other than the Middle Earth mages (who I guess would be Sorcerers?), in many fantasy settings, the quest for digging up old lore and legends was just the means to an end: to fulfill the potential of their true power.
So I don't think overgeeked was far from the mark.