When you age you go back to the core of what you were as a rookie.
For instance a situational passrusher as a rookie turns into an all around defender as he hits his peak, and then as he declines goes back to being a situational passrusher.
Cam entere the league as an elite run defender, improved himself to become a great passrusher, and now that he's lost that explosiveness he's going to end his career as a run defender.
Comparing him to Miller is apples to turnips.
Von came in as a passrusher and will end his career as one.