Those IQ charts look very different depending on who is doing the sampling. One of the famous ones is from a self described "scientific racist".

https://en.wikipedia.org/wiki/Richard_Lynn

My sibling comment understates the critique. There is no such thing as "average IQ". Countries don't IQ test representative samples of their population, so hucksters like Richard Lynn just make shit up and pull samples from mental institutions (where IQ tests are used, as they should be, as diagnostics).

This is a pretty simple and obvious observation. Have you ever been asked to take a proctored IQ test to help establish the "average IQ" of your own country? Presumably not. So why do people keep getting took by this silly idea that "average IQ per country" is a thing?