The humans in the video shot easy balls to the robot, which returns more difficult balls. It's the human that is doing all the running. The robot is quite static. However with better software and better hardware is possible that the robot will be so fast that it will miss no ball, and so strong to return balls faster than any human can reach. So there is no need to play fine shots. That could be a goal if we want to provide automated training partners to humans. If we want to win games against humans, stronger and faster is more than enough.