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.

>>5
That is precisely what is going to happen in Europe sooner of later
I.e. Europe never had any programs for assimilation of immigrants, meaning they are there for economic exploitation and for future massacre.