Trevor Siemian has elite stats when he's playing with the lead.
That's irrelevant though, because you obviously don't factor offensive scheme and play calling into your evaluation of Wilson. Else you wouldn't denigrate Lynch's influence on the Seahawks offense all the time, or twist Wilson's run option plays into his favor.
How exactly have the Cowboys not built a team around Prescott, when he has the 2016 Coach of the Year, three 2016 All-Pros on the OL, a 2016 All-Pro RB, a 2014 All-Pro WR and a 2012 All-Pro TE?
The Seahawks have certainly tried to build a team around Wilson, it's just that pretty much all of the high draft picks they have invested into the offense have failed. Meanwhile his defense is filled with All-Pros.
The idea that Luck has a great team and coaching staff around him is laughable.