Actually, let’s not

Japan - 98% Japanese
China - 91.5% Han Chinese, with the remainder being other Chinese ethnic groups
South Korea - 99% Korean ethnic background
Vietnam - 85% Kinh, with the remainder being significantly small populations of other ethnic groups native to the region

Things do get less homogenous in the pacific island nations, though generally, they are 75% plus native peoples, and the majority of the rest is often Chinese.

US:
White - 60% including Eastern and Western European migrants with no centralized culture
Black - 13.4%
Hispanic - 18.5%
Asian - 5.9%

I understand that this is low resolution numbers, and I am not saying that there is not diversity in these countries. But it is not a ludicrous claim by any stretch of the imagination.

It is not a matter of simplicity or complexity that is a hard pill to swallow. It is obeying authority. An authority which, to damookster’s point in bringing this information, does not sit on this solid bedrock of knowledge to demand this command.

Actually, it is the opposite of what you said. Less people would have to be doing more complex things. Older people and health-compromised people would need to be more cautious, retirement homes, hospices, etc would have to have more strict screenings... This would be more possible than enforcing and expecting every citizen to do any one thing, no matter how simple.