Judging by any Stockholm coffee shop as well we’re all programmers, so the math checks out.
The US and UK (and less so Germany, France, Israel and Japan) produce a sizable majority of software products, especially at an enterprise level. At a per capita level, that gap is even larger with China; and countries like Sweden and Norway become top players.
China’s per capita software production is dragged down by its massive rural population, many of whom have never even owned a computer other than a smartphone. If you don’t account for that, then obviously wealthier/more urbanized countries will have higher per capita production.
However 1 in 5 are 'migrant workers' with no fixed address. I'd guess they are the least educated demographic.
Or you accept that a comparison simply can't be made and don't make the argument in the first place.