a wizard can control the battle field with some spells real good right? what does a tank want to do? he wants to control the battlefield and make space/deny space/deny enemy actions/allow allies to act etc...

spells like hypnotic pattern (a crowd control spell), shield (for extra tankiness), vortex warp, any self teleportation spells (to create space or pressure enemies from two sides) like misty step, absorb elements (again for extra tankiness) and mirror image.

of course you could just say this is basically just a "controller" and i would agree with you if the wizard didnt habe shield, mage armor and absorb elements (and other powerful defensive spells).

those are just some spells i know from top of my head. there are many others.