Soups, stews and roasts made from tougher cuts of meat require long cooking times at relatively low temperatures because it takes time for the tough connective tissue to break down and melt into the dish.
And many preparations taste better after being cooked, cooled and reheated because flavor compounds continue to develop even after cooking has stopped. Spaghetti sauce, lasagna, beef stew, etc., are examples of this.
But dishes made from tender cuts of meat, or meatless, can be delicious and take much less time to make.
The trouble with eating Italian food is that five or six days later you're hungry again. ~ George Miller