~That helps a bit, but if you watch the video, you can see that the cheats have become so sophisticated that even a server wouldn't be able to track them. Stuff like offloading display output to a 2nd computer, identifying enemy players and spoofing a mouse's inputs via a microcontroller to move your mouse to the enemy as if it were a "real" player.

Anti-cheat in general is simply unable to monitor systems at that level of physical complexity, server or client.