The vast majority of humans are lactose intolerant. I sort of get your point but mine still stands. Especially considering in America the percentage is 36% even though we are by majority white still

https://worldpopulationreview.com/country-rankings/lactose-intolerance-by-country

Sort that data and you'll see a lot of countries even higher.

I think the real reason this issue is not known about is because it involves poop and that's a taboo topic that embarrasses people.

Growing up, and still today, if I just went by popular discourse, it would seem to be less than 10%