Well the worth of proper delegation is one of the first things they teach you in business management courses, though not everyone goes through those of course (I didn't, just read stuff on the subject).
But not everyone is comfortable as a leader and manager of men, purely being a creator is what fits those folks best. It's the independent creators who often have the most issues with resource and time management and learn lessons about cooperation that few books teach.
Books teach little. There is no faculadde of life. Just traveling the journey!