The most common form is just another lens that clips on top of the VR lens so it's not something that will require disassembling your expensive VR headset.
This solves the fogging up problem in my experience, along with light leak from thicker arms on glasses pushing foam covers away, scratches on lens from glass/headset contact and also the fact that I broke a pair of glasses wearing them inside a VR headset.
Depends on the type of game, I play flight sims, elite dangerous, no mans sky and project cars 2 - no need to shuffle furniture with those.
I have a dream that we'll see a good quality dungeon crawler I can play coop locally with the kids, that's immersive enough to warrant standing, but I don't see it happening.
That said as someone who loves space/flight and driving games VR is an unalloyed win for me.
For other sims I have to set up the HOTAS on my desk which leads to a little bit of shuffling around.