For many questions in math and philosophy, getting answers earlier does not matter much.

I disagree completely. Looking at all of the problems to solve, the one area that lags noticeably behind in its duties is philosophy. The hardest questions raised in Superintelligence are philosophical problems of value, of what we even mean by "value". I believe that philosophy must be done by scientists, since we need to find actual answers to questions. For example, one could understand nothing of ethics without first understanding evolution. So it's true that philosophical advances rely on scientific ones. But philosophers haven't even learned how to ask testable questions or frame hypotheses yet. The ideal allocation of resources, if a world dictator were inclined to reduce existential risk, would be to slow all scientific advance and wait for philosophy to catch up with it. Additionally, philosophy presents fewer existential risks than any (other?) science.