Kessel's top icetime linemate on the Pens was Malkin for both cup years and all of his PPG years
Kessel has always been able to create offense on his own, but he never "drove" offense in a sense that he made lesser linemates more productive.
As for Skinner, you were watching different games than I was if you saw him not trying under Kreuger on the 4th line. He was crashing the net, whacking at goalies, getting his teeth kicked in trying to create offense by himself every game. Problem was he was playing with Sobotka (who actually had completely given up caring or trying), or other non-driving players like Sheary, Lazar and Johansson.
Skinner is a goal scorer and a pest. To say that a quote about a player like him not scoring goals being a problem.... is that supposed to be some kind of miraculous epiphany?
He is a flawed player, but he is a useful player *if* used correctly. Most cup teams have a player like Skinner potting goals that are weak on D. Chicago had Kane. Washington has Kusnetzov. The Pens had Kessel in their last two cups, and a 75 year old Sykora in their cup 15 years ago. St. Louis had Tarasenko. Kings had Penner. The list goes on and on.
Is Skinner a great player? no, but if used correctly, he can be a positive value. Buying him out would be 6 years of cap penalty. I think you wait at least one more season before contemplating that (2025) when the team will be desperate for cap and Skinner will likely be trending downward more than he currently is.