Same problem as VR treadmills. Tweaking your feet can't fool the accelerometer in your inner ear. Any movement that involves acceleration (all of them) will be wrong. It will never feel like natural movement.
I wonder if there has been any progress on increasing the capabilities of that system. It could just be another component attached to the HMD. I bet as it is now though, even with improvements, it would make you sick, which VR already has trouble with.
https://ieeexplore.ieee.org/document/9714040 https://youtu.be/z91PZpejFeE?feature=shared
Pretty neat
Excerpt: "The sensation is undeniable. The direction of the tip is dependent on the direction of the current, as evidenced by just swapping the electrodes. Obviously, since these were batteries, this was a DC current. Sensation grew stronger over a brief period of time until it saturated. It sort of feels like someone pushing or pulling you over, except there is no tug on your arm. The ramp-up in the feeling made me think of charging a small capacitor."
I remember it pretty clearly even today, which is weird because I tend to but remember this very well, but maybe it was just the excitement of the experiment. It was a relatively strong effect, and it was fairly easy to achieve (of I could do it with my crude setup, a real product should have no problem), but there were some distinct issues.
First of all, there was a lag in response, and it was a pretty large one. IIRC, it took at least half a second before I started noticing any change after turning on the current.
Next, it was fairly binary, and single axis. I could tilt left/right, but that was it, no front/back. It took time to ramp up to full tilt, and then I could only achieve about 50% tilt.
I briefly forgot what I was working with and thought I might try to limit the sensation by pulse width modulation of electrical signal. That was quite a shock! I mean that seriously!
Anyway, I came away from the experience feeling slightly nauseous and that GVS was too limited to work out.
You could imagine supporting yourself with a harness so you wouldn't fall, but certainly you can also imagine that constantly struggling against a harness won't feel like natural walking either.
And there's also proprioception that will sense that your limbs are not moving in the way your inner ear predicts they should. Proprioception can't be fooled. If it could your limbs would get out of sync with your brain and who knows what chaos would result.
Unfortunately we won't be running around freely in arbitrary VR environments until the invention of The Matrix's brain jack. So, not likely within our lifetimes.
Almost none of the human senses are absolute. They are holistic, subjective, and relative to experience (both recent and past), culture, age, etc. Honestly, the fact that we can get any semblance of objective communication of our senses together, based on how wonky and unreliable the individual parts can be, is amazing.
Have you ever been to a "mystery" house/spot?