More favourite useless wizard archetypes:
Wizard who knows exactly four spells, and who suffers from the world's worst case of "when all you have is a hammer" syndrome
Wizard whose magic has predictable side effects that it somehow never occurs to them to take into account until after the fact
Wizard who could have done that at any time, but nobody asked
Wizard whose "magic" is mostly legerdemain, except for one specific, completely unhinged miraculous feat they can do for real
Wizard who's never tried this before, but the theory is sound
Wizard whose powers kind of suck, but who insists they're the greatest in the land, and you can't prove otherwise because you don't know any other wizards
Wizard who wishes to make it clear that they advised against this and will not be held responsible for the consequences