You can't talk about reach with an infrared LOS system, unless it uses a direct laser beam. But even then you would have to contend with walls, coffee cups, paper airplains, wandering pets, and anything else that could inadvertantly block the sensor.
Without the need to run fiber optics everywhere
Still need to put routers everywhere and run wire between them, not like there's anything left of that gigabit potential after a single wall.
You just said yourself you need to run wifi to make this work anyway since it's send only. So you would need to run TWO systems of wiring for ONE interlink.
Gig wifi is not "blocked by a single wall", it's been in use since 2011 and has had no such problems. Plus, an optical system would be blocked by a fly landing on the sensor! And you would only need one access point per room for wifi since it's not LOS, and is two way.
VR would only be a local interlink, between two devices (the computer/console and the headset) not throughout a house. But even then, it's VR, so you'd be moving, the detriment of any LOS system.