Actually, archeological evidence shows that even in extremely harsh environments, many early humans took care of people who were unable to work.

From the article linked below:

"...an idea of what it must have taken to keep Burial 9 alive. Paralyzed from the waist down and with severely limited arm and neck movement, he depended on others to provide food and water, clean him and move him to prevent pressure sores. 'From the bones alone, we can say this person lived with a disease that required help from others to survive,'...

The people who took care of Burial 9, for example, scratched out a precarious existence using stone tools to fish and raise pigs in prehistoric Vietnam. Signs of malnutrition in the bones of people buried nearby suggested famine was a constant threat. 'In a small society which was very stressed, that means somebody who couldn't contribute or go out hunting or undertake a lot of tasks was supported, accommodated, and adjusted to,'"

https://www.npr.org/sections/goatsandsoda/2020/06/17/8788963...