Ok, going to step into the skin color issue.
First, you have to have intelligence to pass it on and the gumption/culture to grow it. Asians, on the whole, push their kids to become more educated but the minority EBT crowd, on the whole, fails their kids miserably. The Congo is smart enough to keep getting whitey to dig their latrines for all these centuries but can’t seem to grasp the dangers of bush meat.
Second, the darker the skin, the less it absorbs Vit D. For lighter skins, it takes 20 minutes of being out in the sunshine to absorb the daily recommended amount of Vit D. Some in the medical field have pushed Vit D supplements for darker skinned during covid.