That's fundamentally why we can do it and animals can't. If humans were unable to store or save, billions of people would die off rapidly. As a species we'd largely stop being so generous & kind with each other. Famines would be common (again). We'd never be able to successfully support such an immense population scale. Operating by a year to year razors edge, is incredibly risky and difficult. Inevitably the mistakes will hammer you. Instead of 10 steps forward and 9 steps backwards (leading to quite slow net population growth), today we're able to make 10 steps forward and maybe 1-2 backwards, leading to immense success overall (whether we're talking about % that make it to old age, or % that survive infancy).
If other animals could store their productivity (including surplus productivity) for 50%-100% of their life span (or more), much less widely distribute/trade it for further self-benefit, it seems like it would lead to fascinating consequences over many generations of evolution.
Sapiens also talks about how humanism is completely made up. Who says a human deserves rights? Why should humans not own other humans? Because we built up a moral system on made up beliefs, largely religious in origin.
And that is good. Otherwise why protect weak humans? Why not just behave more "naturally", like animals?