The things you mention are sudden extremes: famine (extreme hunger), extreme temperature, being hit by a disease. The highest skin cancer group seems to be those that get sporadic extremes of sun (eg. the indoor office worker that burns on the weekend). That kind of rapid change in sunshine quantity was tough to ever do naturally. Even if you could hide from the sun in (rare) caves in the middle of summer it would be for hours not weeks. It wasn't something done normally in life.

I do think we also have observation on our side here, as it has been seen for a long time that people with outdoor occupations have lower skin cancer rates than indoor (eg "Occupational sunlight exposure and melanoma in the U.S. Navy", 1990). Why those stories never broke through to the mainstream is an interesting question.

(I know they're out of fashion now, but the paleo community was talking about doing ~10 minutes of direct sun a day almost two decades ago, with strict guidance to avoid burning, roughly based on the above reasons)

> Why those stories never broke through to the mainstream is an interesting question.

The mainstream media in the US has never been great at communicating any story with nuance or depth. In the 80s and 90s, foods that we've eaten forever were being demonized, like eggs. In 2020, people were being told they shouldn't go outside lest they come within 100 feet of another person.

To their credit, the general population has never had a shorter attention span and so easily hoodwinked into believing misleading claims.

Australia's sun recommendations for people of differing skin types is not bad: https://www.sbs.com.au/news/article/tailored-protection-aust...