The mere act of wasting time while exploring can yield even greater rewards as opposed to just finishing the game hastily. Yes, Fallout games actually justify aimless wandering by encouraging players to get off the beaten path! Who wouldn't want to miss out a chance to venture inside ominous irradiated bunkers, right?
The more time players invest into these games, the more treasures and surprises they discover. Not the Fallout series, these games reward players for taking their time. Other games even discourage players from straying away from the path that leads to their goal. There are games that reward players for finishing fast and those that punish players for going too slow.