It demonstrates Valve have been at this longer than the ~5 years of the Index, and closer to a decade again (the point OP disputes and uses Index as evidence of).
not OP but it does seem like you're nitpicking details instead of engaging with what seems to be the intent of the response: AR/VR has come an incredible distance since DK1, the last 10 years have seen it go from a barely-discussed completely unavailable/fringe dev-kit-only technology to being an clearly viable spectrum of mass-market products.
edited: grammar. still feel like I've failed to produce readable english, but I'm giving up
