Sure, we have various social functions, but they're not supposed to define our whole life, to make sense of the "wasted life" expression. And our biofunctions don't necessarily carry the kind of value that make for the pejorative sense of that expression. A wasted life is supposed to be bad or a shame in a deeper sense than a wasted heart valve or a malfunctioning toe. Of course, we think biological malfunctions are bad if they impact a life, but that's because we assign more value to life than can be derived from a strictly biological description of the naturally selected function. The point is that evolved functions are matters of sheer causality, whereas a fulfilled, nonwasted life requires an unscientific value judgment of some kind.