I believe your answer is because it would allow us to settle down in designated areas and specialize is creating a society.
Explanation:
Prior to agriculture humans had been surviving as nomadic tribes that would follow their hunt to survive. Though, from the development of agriculture members of society could specialize in farming to sustain the population while others could specialize in trading or constructing. This lead to an immense development in our species and survival, and is why you see so many of the modern wonders we see today. (ex: Skyscrapers, World Trade, some cool stuff like: sports, and the internet.) These could most likely have not been achieved or at least not in the span we had without the function of agricultural and cooperating in an civilization.
