What's the metric on "average human" from a global population of > 8 billion people .. and why would they score mid on a standardised IQ test skewed toward western education / culture?

Who said anything about IQ tests?

What specific metric did you have in mind for ranking intelligence and determining average intelligence in this comment: https://news.ycombinator.com/item?id=49560984

You must have some notion of an argument as to why all the varied attributes of different humans should align to all be "average" in some specific human.

O/wise you'd be peddling sloppy trite aphorisms that don't bear scrutiny.

average still means something regardless of how you can define it.