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?