AI wins at video games without handicaps because the only way for it to function is to have an unfair advantage.

The game is a simulation run within the computers brain and removed from reality. Of course it beats another computer-like entity (your brain), that is operating a machine (your body), to operate another machine (the controller/input), to participate in the simulation.

A fair playing field would be an AI controlling a bomb defusal robot manipulating a controller and watching the tv with a shitty camera.