Anivia's W (Wall) not ''impassable''

Anivias W (the wall) says when you hover over it ''creates an impassable wall'' but it kinda annoys me when it says impassable since by definition impassable means ''impossible to travel along or over.'' although some champions like Zed and Maokai can teleport and go under the wall why is it that Champs such as Fizz and Talon can go over the wall? and Camille does whatever she does