While he certainly has not had a great year, the team around him is less than average.
That said, it is the curse of the QB that makes running the ball a key part of his game. Eventually these monsters falling on it, clobbering you, twisting your legs in the heap, etc. takes its toll. The injuries mount up, the QB doesn't want to use his legs much anymore, and there goes the key to his game.
And before anyone gives me a couple of names of running QBs that have succeeded, there's probably 5 to 1 of those who eventually lost their game. Look at Cam Newton. Michael Vick started to get beat up and it slowed his running effort and suddenly he became ordinary. Already Lamar Jackson is starting to get nicked up and is a little more reluctant to run. I can see Arizona's Murphy falling into that same category sooner than later because he's so darn small by NFL standards and his running is critical to the success of the Cards. It will eventually bite Allen of Buffalo, too.
Wentz will probably do better when he has a better team around him. But he'll never again be the Wentz of his first 2 years in the league.
