In practice the south is more "racially diverse" than the Bay Area, because minorities can actually afford to live near white people. Coming from Atlanta it was shocking to me how homogenous the Bay Area was.
55% of the Bay area is Hispanic, Asian, or Pacific Islander. The major point how they differ is that the south has far more black people and fewer hispanics and Asians, vs the bay area having far more hispanics and Asians and far fewer blacks.
But in say Palo Alto, you’ll rarely see black or Hispanic people outside service roles. It’s 85% non-Hispanic white or Asian, which is about as diverse as Wyoming. The south is economically flatter, which means people mix more. Also, because of its affordability, the south is the major destination for upwardly mobile black and Hispanic people.
