He's shown what he can do in glimpses. It's Wenger that has fitted the handbreak, I bet you.
We play one way, pass the opposition to death, make them run. When you are up against a (let's face it) kick and rush team who have genuine quality up front then the midfield Wenger relies on just gets bypassed.
Ozil should have been told to run at them every time he got the ball, shoot every time he caught sight. But not Wenger's way.