Marques Brownlee picks out the quality of the eye tracking as a standout feature.
Drawing is a task that is more like aiming - attempting to hold your gaze at a precise location for a period of time. It is possible, but you are fighting against the natural saccade pattern of your eye and it becomes tiring very quickly. You can expect fatigue / eye-strain within a few minutes.
A new platform certainly doesn't have to be better at every task.
Even 20 years ago, a professional digital illustrator wouldn't try to draw everything on screen with a mouse, they would have a tool more suited to the task, like a Wacom tablet.