Most challenges we can approach with trial-and-error, so many of our habits and social structures are set up to encourage this.

This hasn't always been the case. Throughout history leader have had to get it right the first time. Especially in war-times. I'd bet that someone more versed in history than I could give lots of examples. Granted in our current society which is saturated with complexity and the limits of human comprehension trial-and-error seems like a viable way. But hierachical processes seem to work quite well for major human endeavors like th manhatten project.