Still trying to understand your argument. What are all these diverse countries? You talk about Nordic countries as being so uniquely homogeous and then you say Switzerland isn't diverse, so what exactly are all these developed diverse countries?

Could you give some examples of countries which are markedly more heterogenous than Nordic countries, because I frankly don't grasp what countries you have in mind. If we are such an outlier should be able to mention at least 5 diverse and developed countries.