Doctors are busy people. They are too busy saving people’s lives and curing them off their illnesses. Asking them to write long reports would be a waste of their time, and they would rather relax after their long day’s work instead of writing reports about their patients.
This apparently means work for other people. Doctors make medical codes on their report sheets, and this gives jobs for people who learn medical coding training courses to do the detailed report creation work for the doctors.