FWIW, there's also happened quite a lot of research on latency in academia - which that page seems to completely ignore.

My group has been looking into that topic, too¹. One of our most interesting findings (IMHO) was that for many USB devices, input latency does not follow a normal distribution but that each device has its own distribution of latencies for input events, including funny gaps².

However, with gaming hardware supporting 1000+ Hz polling, the effect of input latency should be negligible nowadays.

¹) https://hci.ur.de/projects/latency

²) https://epub.uni-regensburg.de/40182/1/On_the_Latency_of_USB...