Unlike preparing lessons and tests, grading papers and homework etc which takes no time and effort at all...
My Brother was a teacher. He spent a lot of time outside the classroom doing school related work. He probably devoted most of his life to teaching. I visited his classes a couple of times and I hate to say it but he was not a very good teacher.
My Grandfather was also a teacher and principal. When I was younger I was constantly running into people who were taught by him. I could always expect the same statement: “He was the best teacher I ever had”.
One day I asked my Father if Granddaddy spent much time out of the classroom working on his school teaching. Daddy told my he never spent a minute on class work outside of school. Granddaddy was a truly brilliant man and he just didn’t need to prepare any lessons etc. If he graded papers he would do it at school.
Coaches also have this responsibility along with the other things...