In the future, why couldn't we have VR that didn't require you to wear a headset, that felt, smelt, looked and tasted just like the physical universe in every w

In the future, why couldn't we have VR that didn't require you to wear a headset, that felt, smelt, looked and tasted just like the physical universe in every way? I can't begin to imagine what kind of technology we'd be talking about here - other than some kind of implant that effectively hijacked your entire central nervous system. Would it really matter that the VR universe is "made-up"? Beats me, but we're dealing with pure hypotheticals here.