>>290157159
I'd put it down as there being no standard as you said, though I feel like we're moving towards one.
That and the fact that the technology behind it all it is being poked and prodded trying to find the best solution. Lenses, controllers, tracking, and the current goal of eye tracking for foveated rendering.

Lots of little things that are still being hammered out both in terms of small individual scale and on a larger market scale.