It's kindof a lot of stuff... His 3pt shot has completely disappeared, he's not wide enough to set quality screens, he's got a negative assist to turnover ratio, he's not great at picking his spots on offense, like for every one of those sick coast to coast layups there are 3 record scratching possessions that end in a turnover.

IMO his biggest problem is on the other end of the floor. His length gives him the ability to contest a ton of shots, but his lack of mobility and unique body makes him exploitable. He's often too frail to hang with even smaller big guys in the post and too slow to guard on the perimeter or in space.

I think if you built a lineup around his strengths you could overcome his weaknesses, but he's not a guy who's worth the effort right now. I'm always rooting for him but I think he's right on the fringe of being out of the league.