Diversity is a strength?

can someone explain to me how diversity is a "strength"? what exactly is the benefit of mixing people of random languages, religions, ancestries, eye colors, hair colors, height, weight, intelligence, sexual orientations, disabilities, and classes in a small localized area and forcing them to reproduce with one another? because this has never resulted in a single discovery or invention. only poverty, criminality, disease, and civil strife.

differences in people are the number one cause of war. stop the hate. separate. give every group their own land.

Throughout history the rich have adopted other cultures, as a sign of cosmopolitan sophistication and superiority over the peasants who rarely traveled. Multiculturalism and diversity is basically a continuation of this.

Logically you could argue that there is no reason for attempting to force either monoculturalism or multiculturalism on the population, merely not flipping your shit over the presence of someone with a different culture is enough.

But then, who cares?