The second thought – that we try to make things better – is shared by every plausible moral system and every decent person.

I don't think that's the case. Karma based moral systems work quite well without it.

There a scene in "The way of the Peaceful Warrior" where the main person asks the wise man why the wise man doesn't do something substantial with his life but works in filling station. He replies that he's "at service" in the filling station. The act of being "of service" is more important than the value created with it. It's especially better than "trying" to do something from that perspective.