An axiom of liberal thought these days is that culture is coextensive with race. Hence the dichotomy asserted in the curriculum materials I linked: disparities must be geographic in nature; any other theory is “racist.” (Likewise, most of what’s attributed to “whiteness” is really Western European culture. They don’t seem to distinguish the two concepts at all.) There is no room for the possibility that different societies developed different cultures for various reasons, and certain cultural traits may be better adapted to economic development than others.
Fun fact: Lee Kuan Yew’s (the founder of modern Singapore) birth name was Harry and his first language was English.
Sowell used to write very well on race and culture stuff eg https://www.amazon.co.uk/Race-Culture-Sowell/dp/0465067972
He could get away with saying things that would otherwise be regarded as politically incorrect as he is black himself. It's a shame there doesn't seem to be much of that quality any more.
I think a lot of what makes the difference is cultural. Places like Singapore have a culture of hard work, rule of law, free trade and so on, mostly brought in by its founder who got a lot of that stuff from books and learning. There is hope to replicate those sort of things gradually. It's not so much about race - Singapore is quite the mix - the founder was Chinese but studied in England and the people are a mix of Chinese, Malay, Indian, Westerners and other.