I would say that the value for a star in having a good midrange game is that if you can shoot 3s and get to the rim, in the playoffs a good defense will force you into mid-range shots. If you can make them you break the defense and force changes that open up more offense for yourself and others. If you can't efficiently punish it, they'll force you to either take and miss mid-ranges or make really hard passes, or dribble into multiple defenders all of which open up turnovers and breaks.