Getting one&#x27;s hands dirty at a technical level is incredibly difficult. Bill Gates&#x27;s training and experience is in computer science and business; to develop the background needed to understand the details of treatment for Malaria, HIV&#x2F;AIDS, etc would take many many years of intense, focused effort.<p>Someone like Bill Gates could hire someone with the technical expertise while spending his own time on more productive things that are likely to yield more good for the world--networking with other billionaires to convince them to donate money, working to manage the overall structure of the B&amp;M Gates Foundation, etc.<p>Complex systems are complex. 200 years ago, the amount that we knew was significantly smaller; one could get to the edge of human knowledge with just a few years of intense work. In contrast, it takes significantly longer to get to a level of expertise at which one can productively contribute.