You're right, it's not currently a concern because most people would never think of VR as more than just a 15-20 minute experience.
However, I have read a lot about people who get VR sickness. When you dig deep, most of these people are playing on Quest or a 90hz headset. Yes, most people will get used to it, but it can ruin your experience and keep you from playing a major RPG in VR. Right now very few headsets hit 120hz and only the Index can (kinda) hit 144hz.
Moreover, VR has yet to become comfortable. At the moment, the PSVR is the most comfortable, but even that can get uncomfortable. The Index comes in 2nd, but it also begins to get uncomfortable for long play sessions.
Field of view is huge for the experience. Right now, even a Pimax feels like you're wearing SCUBA goggles. Once we get to human vision, you'll be INSIDE the holodeck, rather than peeking through a wall.
All these things are holding VR back from mainstream. Microsoft doesn't need to be first to the party. Just like Apple, they just need to do it best and allow others to build the market.
Again, I disagree. I've gotten to spend significant time with psvr, index and quest and I would say the quest is way more comfortable due to it being untethered.
Complaining about the scuba goggle effect is like saying someone can't get immersed in a book because they are physically looking at a page. It isn't a limiting factor of the individual is engaged.
I don't disagree that the tech needs to continue to improve, but it is viable already and a more convincing argument for me would be that more developers need to make games exclusively for VR so that the medium can move forward.