There doesn't seem to be a way to assign a hotkey to toggle between wireframe and shaded mode.
I was able to assign a key to the viewport shading context menu, but that requires me to press a key and then click an option, e.g. Wireframe or Shaded. This at least allows me to hide the cluttered viewport Header, but it doesn't save me any mouse miles or clicks.
I was able to assign a key to enable Wireframe Overlay, but that's not what I'm asking about. I want to switch between Wireframe display and Shaded display with a single keystroke... like in every other 3D program I've ever used.