As an aside, I'm also suspicious of research that shows ~100ms as the threshold for "instantaneous" action, because in video games like FPS shooters most players seem to dislike playing on ping that high.
Even locally, FPS games can reach upwards of 100ms latency locally even before hitting the network, so 100ms ping is more like 100+100=200ms of latency. http://renderingpipeline.com/2013/09/measuring-input-latency...
Additionally, we're extra sensitive to things like latency between a tablet pen drawing and it's stroke appearing, or rendering lagging behind VR HMD rotation, or audio latency if we're trying to jam. Even if we register ~100ms as "instantaneous" in a lot of scenarios, it can still cause troubling disconnects between action and result.
John Carmack on VR HMD latency: https://danluu.com/latency-mitigation/
John Carmack noting that depressing a 360 gamepad trigger can take 20ms: https://twitter.com/id_aa_carmack/status/233240260568551425
A Microsoft Research video on tablet input latency, where the effects of 100ms vs 1ms latency are clearly visible: https://www.youtube.com/watch?v=vOvQCPLkPt4