It’s a common elemental theme we see across stories, fantasies, etc. It seems like it is an element that should be part of that pantheon but maybe there is a scientific explanation of why it isn’t? Or is it simply, they did not have enough understanding of it at the time those 4 were suggested.
matter for earth, not sure about air. this kind of falls apart now :x
Maybe the ability to separate the nitrogen/oxygen/carbon dioxide and direct them? That would be cool and could make up for it. Just straight suffocate someone with the air around them?
They actually show that at some point.