Kreider definitely is the main driver in this team, but Zibanejad was scoring with Fast and Namestnikov, 2 bottom 6 players. He will be fine without Zucc and Kreider.I'd argue he was the primary driver of the Wolski-Stepan-Zuccarello line in 2010-11 and the Clowe/Pyatt-Richards-Zuccarello lines in 2013 as well.
And while Kreider may have been the primary driver in 2016-17, Nash in 2017-18 and Kreider/Hayes in 2018-19 I don't think its fair to characterize Zuccarello as a passenger outside certain stretches.
E: I want to emphasize that my position is also that Kreider, not Zibanejad, is the primary driver on the current line.