In 2018-19, Zibanejad reached a new level in his career with 30 goals and 44 assists (74 pts) in 82 games. Note that he is also a defensive center, used in defensive situations and on the PK. He is really far from an one-dimensionnal offensive player. 74 in 82 is pretty close to PPG and Panarin was still in Columbus...
Now for 2019-20 and 2020-21, a pretty good tool to find the line combinations (if you can't watch enough games to know basic stuff like this)
Line Combinations - Frozen Tools
As you can see, didn't play much with Panarin at ES. Only 13 of his 43 (30%) ES pts were with Panarin on the ice (so it doesn't mean that Panarin made a big play for the goal to happen). Maybe 1 or 2 more pts as the tool doesn't show all the combinations for some reason.
Same thing for 2020-21, even less time at ES together. Only 8 of his 32 (25%) ES Pts came with Panarin on the ice.
Line Combinations - Frozen Tools
Yes, obviously he has been playing on the PP with Panarin. Which team in its right mind wouldn't play their best players on the same PP unit? The objective is to score goals and that's what they do. This is a very ridiculous argument, Zibanejad isn't a "pure product" of Panarin. Like as ridiculous and ignorant as "show me a Draisaitl PPG season without McDavid!"