collapse of the old society

Like I said IQ should never, ever be used as an entry exam or any other kind of social determinant. Not least because of the racist/classist history. However, it does have a signification and legitimate uses, and to pretend otherwise is scientific negationism. We do not have to listen to racist conspiracy theories about why some populations have a lower IQ than "us", when we have known and repeatedly demonstrated for many decades that differences in IQ at the population level is entirely predictable by education and health (the Flynn Effect). That's it, that's the necessary and sufficient counter-argument to the racist arguments you're referring to.

Put another way, education does not just make people educated; it makes them more intelligent. Someone who has gone through standard schooling is empirically proven to be statistically better at novel abstract thinking than someone who never went to school. Which is kind of obvious when put like that, but you can't prove or study that phenomenon scientifically without the use of tools like the IQ test.

Poor african countries have a lower IQ than the world average, and that is an irrefutable fact. Does that mean:
a) Life outcomes are not shaped in anyway by socioeconomic background, therefore [insert racist theory here]
b) I refuse to look into the possible causes and therefore IQ tests are racist
c) We can infer that poor populations would benefit from increased financing of childcare and education, it's a winning move for literally everyone.

The topic of IQ tests is really uncomfortable because it unearths the really uncomfortable fact that socioeconomic and geopolitical factors have not given us all an equal shot at life, even down to how intelligent we are likely to become as adults. It challenges the myth that anyone can just pull themselves up by the bootstraps, work at mcdonald's, and become a triple harvard graduate. But it's not neuroscience's fault that the world is unfair.