Make no mistake most humans will exploit any glitches and bugs they can find for personal advantage in game. It’s just machines can exploit timing bugs better.
Some people are able to do frame perfect inputs semi consistently from what I understand. I don’t understand how, as my own performance is around hitting 100ms window once, every other time
If you're using a typical PC (or $deity forbid, a phone) with a typical consumer OS, there's several sources of variability between your controller and the visual feedback you receive from the game, each of which could randomly introduce delays on the order of milliseconds or more. That "randomly" here is the key phrase - lag itself is not a problem, the variability is.
