Another important missing factor here is the modeling of empathy and altruism. It can often simply
feel good to help someone else, even if you get nothing tangible in return. This is a biological fact, as far as I'm aware.
Incredibly crude approximation: some situations that appear as [empathetic helper +0, receiver +3] on the surface, might in reality be [empathetic helper +1, receiver +3].
There is a ton of complexity in how this works in the real world. The magnitude or presence of the non-tangible reward may depend heavily on a certain aspects of one's value system. It may be heavily contextual -- only certain situations foster the non-tangible reward. Sometimes there is a potential tangible reward that may come much later, after some weeks, months, or years. And so on... I think this is barely scratching the surface.
Lastly, none of the people or dynamics in the system are static.
The linked interactive tool was very cool. However, I'm increasingly skeptical of these types of analyses as they generally are forced to ignore most of the complexity of the real world.
EDIT: I completely forgot about technology... things like the internet which completely change the nature of an interaction between people, or apps that mediate or flavor in-person interactions in ways that society has never seen before.