Oh, I was mostly describing network latency and file IO cough should apply to mouse polling as well but bear in mind what another user has said. For mouse specific concerns, I would take a look at the following tutorial:
Thanks! Curious, why changing network/disk IO latency, does it help in online games noticeably?
It does, even when navigating the web.
By decreasing latency, you decrease throughput. Thus if you have a slow and old computer, you could end up dropping inputs entirely by decreasing latency, or make it feel sluggish/laggy due to it processing a queue.
You're correct, I should add something to my post.
For older devices, the most gain would probably come from using a lower resolution input and a lower resolution output (to match what was available at the time). Throwing a 2k monitor on a graphics card from 2014 is probably going to be a barely passable experience (buffers weren't as big back then), same with mice.