Renaming, pushing variables, changing their types, stuff like that. It's still editing work. Can any IDE split the class into two according to methods' responsibilities? Can it abstract a set of functions to a single generic function? Can it get rid of unnecessary boilerplate code scattered around in various classes? Can it change data structures used to store data?

Because refactoring is about making the code simpler and more flexible. Rearranging that IDEs do is only a method (and not the only one) to achieve that.