So, you rush in, sweep aside the pikes, penetrate the formation and... then what? You stand there, with a weapon incapable of harming your opponent more then a simple bar of steel could, which is not zero but still.
Zweihanders were used to break up pike formations
Eh, not quite. u/wotan_weevil examines this claim re the European two-hander. As a bonus, they also have a post on how to deal with an opponent using one.
As always, if anyone else would like to address the question with a post of their own, please don't let this post stop you!