> Any player responding to ingame events (enemy appeared) with sub 80ms reaction times consistently should be an automatic ban.

It's really much more nuanced than that. Counter-Strike 2 has already implemented this type of feature, and it immediately got some clear false positives. There are many situations where high level players play in a predictive, rather than reactive, manner. Pre-firing is a common strategy that will always look indistinguishable from an inhuman reaction time. So is tap-firing at an angle that you anticipate a an opponent may peek you from.