I predict that air gestures will spread not as a replacement for existing interaction methods, but as an alternative for achieving specific purposes. This is because, although it has been over a decade since smartphones and tablets became widespread, mice and touchpads are still the primary tools for office work. Similarly, even as air gesture recognition becomes more accurate and the necessary sensors become commonplace, I believe they will be used alongside our current input methods.
I agree with this point because I don’t think air gestures will fully replace touchscreens or a mouse. They seem more useful for certain situations where hands-free control is easier, like driving or medical settings. But for tasks that need accuracy, like typing or detailed work, traditional input methods will probably still be better.