On the other hand: So fucking what? You know how the world becomes a better place? By people doing things that are difficult and thankless because those things need to be done. The world doesn't become a better place by people sitting around waiting for the brief moment of inspiration in which they sorta want to solve a local problem.

Historical, isn't that exactly how the world became a better place? Better technology and better institutions are the ingredients of reduced suffering, and both of these see to have developed by people pursuing solutions to their own (very local) problems, like how to make money and how to stop the government from abusing you. Even scientists who work far upstream of any application seem to be more motivated by curiosity and fame than a desire to reduce global suffering.

Of course, modern wealth disparities may have changed the situation. But we should be clear, if we think that we've entered a new historical phase in which the largest future reductions in suffering are going to come from globally-altruistic motivations.