I’m not sure what it means for society to be rewarded, or for society to benefit: I don’t think of “society” as a reward-seeking agent.
I think that the point is that the creators of LW/OB implicitly take that stance, that there is such a thing as a “better” outcome for the whole human race or the whole country, and that we ought to have better institutions to achieve these outcomes. And if you do take that stance, you end up with planning-esque rationality, because “scientific and technological beliefs have large effects on how societies fare, but smaller effects on how individuals fare”
I think that the point is that the creators of LW/OB implicitly take that stance, that there is such a thing as a “better” outcome for the whole human race or the whole country, and that we ought to have better institutions to achieve these outcomes. And if you do take that stance, you end up with planning-esque rationality, because “scientific and technological beliefs have large effects on how societies fare, but smaller effects on how individuals fare”