Doesn't the projection require one hand to be up and in a flat position, and the other hand interacts with it? Meaning it requires two hands?

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!

From the demo video it looks that buttons can activate with similar pinch gesture as new Apple watch has.

"What comes next" is interesting as a problem formulation insofar as it encourages solution based thinking ("Here's the solution I think is next, for an problem still to be identified- other than it is what comes next.)

> People are thinking about the form factor after the cell phone.

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.