One possible reason why dessert is often served with the main course in a meal is to provide diners with something sweet and satisfying at the end of their meal.  Sweets are a great way to finish off a savory dish, as they can provide an extra burst of flavor and texture.  Additionally, desserts are usually associated with special occasions and celebrations, making them a great way to add a celebratory touch to any meal.  Some desserts are designed to be shared, making the dining experience more social and enjoyable for those gathered around the table.  Lastly, dessert is sometimes served alongside main courses to give meals an extra sweet ending that diners can look forward to.