Funny then that nobody I know that uses it complains about the input lag. (Similarly to how input lag in TVs etc is not something people outside dedicated gamers really care about. Plenty people are quite tolerant/don't know what they are missing)
I believe their main point is that humans are much more tolerant of latencies than is commonly assumed. I remember reading about Carmack's early work with VR and sensor delays and screen refresh delays on the order of 100ms and as high as 400ms and it still being enjoyable[1]. At 60fps you've got about 16ms per frame to work with, and I'm sure the human mind doesn't need input -> change in image within a single frame (though I'm sure pro gamers would notice).
I even see people using and enjoying shadowpc + vr headsets, where delay between head turn and change in image can be nauseating.
[1] https://www.pcgamesn.com/virtual-reality-john-carmacks-battl...