Most likely reason is that you have the worst ball in the game. Your opponents are using better balls.
another factor: knowing the course and where the best bounce/roll is going to occur
another factor: Wind. A lot of guys will hit their shot to go into the wind from beginning to end. Ideally, you want to hit your shot so that the wind is help you at the end of the shot. Example. Wind is blowing left to right. You want to hit your shot so that it lands and rolls on the right side of the fairway, which means the ball was fighting the wind for half the airtime and riding the wind for the other half. if you aim to land it on the left, the ball pretty much fought the wind the whole way