It is the daily torment that makes him the savior Titan that he is. He is in a very real sense the father of what makes us different from the other animals. Prometheus gave us the likeness to the Gods that the other animals do not have — a likeness of mind. Prometheus saw that we have the potential to excel and create in a way second only to the Gods themselves. By his gift of fire, which can also be seen metaphorically, we are able to harness this creative drive.
The suffering of Prometheus also gives us an example of endurance. Even if we are not going to have to endure the daily eating of our liver, we have our daily trials. For some of us, it is physical issues; for others, it is mental. But the example of Prometheus shows us that we have the strength within us if we bother to look for it.