What is 'objective' value?

[Angrboda]

Objective value is based on facts, not opinions. Food has value. Water has value. We need both to stay alive, we all can objectively agree on that. It's not anyone's opinion that we require water and food to stay alive, it is factually true. Subjective value is based on opinion. My iphone has subjective value...I find it valuable, but another person might not. Things that we think we need are usually based on subjective values, whereas things that we do factually need, are based on objective value. Just my take, anyways.

Food and water only have value insofar as they matter to the project of being alive. They acquire their value as a consequence of their utility to a subjective value, namely that of living. Food, water, and living have no value independent of that. They do not have objective value by the route you propose. They are simply aspects of our subjectively valuing being alive.