The fact that the Germanics were so far behind the Romans and Greeks despite the fact they're all Europeans and are genetically related is the greatest proof that race does not actually matter. If race did matter, they would all be on equal levels, but this was not the case. The Romans and Greeks had amazing, technologically advanced civilisations where they would do advanced mathematics, philosophy, etc. along with stunning buildings like the colosseums and temples. Meanwhile, the Germanics were uncivilised and lived in mud huts and sat in bogs.
If the Germanics went from living in mud huts to being first world highly developed countries, there is no reason why it would not be possible for third world places like Africa to do the same.