Being able to handle the basketball and make quick moves comes down to being comfortable with the basketball. If a player is not comfortable handling the basketball, they will have to slow down to make their move or they will end up turning the ball over when they try to make their move. This dribbling drill is going to allow the player to really develop their handles by having them quickly go from making move to move without stopping.
Along with working on handles, this drill also does a great job of developing a players footwork. Going in and out of the cones each time forces the player to really have quick and light feet as they do the drill. Footwork translates into so many parts of the game of basketball, so anytime you can improve on it is a plus.