Virtual Reality will not reach total immersion unless they can override all sensory from the body and replace it with the virtual experience.
What they are doing right now is creating a workable virtual reality that brings enough immersion to the table to be a truly new entertainment experience. VR wasn't very functional before because the technology couldn't bring position tracking into play in a way that would keep someone from getting motion sickness.
All the big players in the VR industry say were are in the very early days of the technology, that it won't be a full, broad audience experience at least for a decade or two.