It has the potential to be inefficient if they choose the wrong group of scientific advisors. But, for most of these initiatives, they're very careful to choose smart people to actually lead the details of the project and figure out how to best distribute the money.

Sometimes, we're actually within striking zone of these targeted diseases and funding more translational research is good. Other times, we still don't understand the underlying diseases well enough, and so we still need to do an enormous amount of basic science before trying to cure these diseases in the clinic. A team of good scientific advisors who are at the cutting edge of their respective fields can provide the insight and decision-making that this needs, to extract the maximum value from the money provided.

They are not on the driver seat. They fund and observe. This system is better than state or academia.

OK, who should it be driven by then? A monarch? Democratic vote?

https://en.wikipedia.org/wiki/Patronage