We have next to no idea what life would be like if aging were really optional, as others in this thread have pointed out. Some of us work on the biology of aging mainly out of intellectual curiosity, sure; I don't think many of us do so out of a certainty that there would be specific benefits to society (wealth, wisdom, whatever). There is a third category of motivation, however, which plays a large part for some of us (myself included): simple, unreasoned, visceral dislike of the phenomenon of human aging, and belief that it is an affront to human dignity. This may not be very scientific, but it's human, and as such it's a legitimate reason to decide what to work on.

Aubrey de Grey