In 20-30 years, it is highly likely that we will have seen one of two outcomes play out: either LOTS of people use it, or virtually NOBODY uses it because something better has come along.
Probably more like 2-3 years on that.
You may be right, although it is difficult to know just how long it will take.
I'm curious to know whether Ed has thought of an answer to my question from a few posts back.