I don’t think in 1926 more than 50% of global 15-20 year olds could:

“acquire food from nature (farm, hunt, gather) and cook it for themselves.”

Or

“make and fix their own tools. Build and fix their shelter.”

(Culturally, those tasks often specialize by vocation, gender etc.)

I don't know about "globally" but I would be surprised if 50% of American males couldn't do this in 1926. These were skills taught to most young males and the country was far more rural. It was far less universal among females though some did learn these skills.

While unstructured, this kind of standard life knowledge was intentionally and systematically passed down to most boys in every community I lived even when in elementary school. It was expected that you knew how to do these things and men would go out of their way to teach you if you didn't.

Kids did fishing, trapping, hunting, building out camp sites, etc for fun when I was growing up and it was generally encouraged. Learned helplessness wasn't really a thing.

This started to die out decades ago. Most zoomers I know didn't have anything like this experience.

They absolutely could. A quarter of Americans’ primary job was agriculture in the 1920s. While job specialization was certainly a thing that didn’t mean people outsourced all of these tasks the way people do today.