People are thinking about the form factor after the cell phone. Apple is busy training everyone to use hand gestures with the new Apple Watch and upcoming Apple Vision. Humane is going down the path of projecting on the hand and touch.
Apple's implementations are for 1 hand operation. You can operate the watch's touch screen while holding a steering wheel for example.
What's the difference between the objectively not great screen that is my hand, and the oled watch that doesn't require both my hands for operation?
EDIT Heck this requires one hand just to see anything. I can look at my watch without any hands!
That presumes there is one. There's not yet a "form factor after the car" for example. Just refinement of the same basic 4-wheeled template, with a few oddball vehicles for niche uses.
A possible indicator here is the apparent lack of demand for small screen phones. To me it suggests that screen real estate is more valuable than portability for most people.