He'd be great in the Midfield full time but it's hard trying to fit all of Shuey, Yeo, Kelly, Gaff, Sheed & Redden in there... Sheed & Redden are the two that have been pushed out and have become part-time mids. Kelly's unexpected arrival hurt his midfield minutes.
He's really knows how to hunt the footy, so I'm sure he's a little disappointed in his reduced midfield role. But he's a crucial part of the rotation though, and as evidenced on Grand Final Day 2018... He knows how to go forward and kick a big goal.
But you are right, at a lot of other clubs he'd definitely be a permanent mid.