You have to be somewhat insane to be a major SV investor. It's a lot of money with huge risks, and it doesn't pay off most of the time. For every A16Z or YC, there are 100 that burned all their raised cash on failures. It's like producing a movie. You put a lot of faith and money in the artists with a creative vision, as your own skills that raised billions of dollars don't translate to successful creative projects. Though drugs can dupe some into believing they have both.