All of those things are already computed on server. The purpouse of anti cheat is to not let computer to game for you. To not precisely click heads, step out of danger within 1ms of seeing it or reliably hit timings and combos. Such things can be hard to detect, and it is an ongoing battle between detectors and cheats. And ordinary people are on the loosing side, as they face forced kernel rootkits, false cheat detections and grace periods during which cheaters are still allowed to play.
All of those things are already computed on server. The purpouse of anti cheat is to not let computer to game for you. To not precisely click heads, step out of danger within 1ms of seeing it or reliably hit timings and combos. Such things can be hard to detect, and it is an ongoing battle between detectors and cheats. And ordinary people are on the loosing side, as they face forced kernel rootkits, false cheat detections and grace periods during which cheaters are still allowed to play.