Too cumbersome.
The mobilephone fits in the hand, and we have grown to accept the desktop computer.

It needs be 0% cumbersome.
No wires, no weight, and cheap enough.

Until it become as mainstream as cocacola, the gameing industry will keep treating as a niche.
That's why you only find new game mechanics in indie games.
The big publishers only go for sure wins.
So another Doom, another OverWatch (I think OverWatch is already another something else).