If everyone agreed on everything, the world would very much be peaceful but also be quite poor and maybe even regressive in terms of human development and technological progress. This is because disagreement and conflict often drive innovation, change, and progress. Consider scientists for instance, they work together and consider each others’ opinions before conducting a dangerous experiment. They are always in communication and that’s the main reason why innovation and development has changed this much in such short time; people consider each others’ ideas and give either positive or negative feedback. For them, disagreeing is always a positive option, since something can result terribly. When people disagree, they are forced to consider alternative perspectives and develop new ideas and solutions. Conflict also motivates one to take action and strive for improvement. In fact, some of the greatest advancements in human history have been the result of conflict or disagreement, such as the scientific revolution and the civil rights movement, or even the protests people perform!
On the other hand, if everyone agreed, there would be no need for debate, compromise, or negotiation, which are essential components of democratic societies. Without these processes, there would be no need for political parties, elections, or other mechanisms of decision-making, which is a huge problem since those are the things that will control our lives. Can you imagine a random man walking, shouting on the streets of New York and telling people that he is the new president? And everyone agreed and believed in him? This would also give a rise to millions of outcomes which controls the life of a person. This is a very serious matter. This lack of diversity, or even in thought and perspective could result in a narrow-minded society that is resistant to change and lacks the creativity necessary to develop new ideas. Not only lack of diversity, but the state of having too many choices would even be overwhelming since even the individual wouldn’t be able choose.
Overall, while a world where everyone agrees may seem peaceful and harmonious on the surface, it could actually stifle progress and development. Disagreement and conflict are necessary for growth, and without them, society could become complacent and stagnant.