What is it exactly that makes Wizards OP?

[Yukitsu]

Depends. At early levels, I make judicious use of a crossbow, sunrods, smoke sticks, acid and alchemists fire. Even tangle foot bags if I'm feeling punchy. You'd be amazed at how many fights end with a pointy stick at the thing glued to the ground that's on fire. The few spells are for special encounters only, ideally, unless the DM gives too much time to rest. At later levels, one spell to end them all and in the darkness bind them as it were. You won't be seeing as much of a percent increase on the field, but you will be seeing more monster attacks on towns, which is where the wizard casts his 9 buffs in a row. (Say goodbye to waterdeep)