Students read lessons and do exercises on their own.
There is no need to repeat content in class.
Use the time for more important things.
Instructors help students one-on-one.
Instructors explain concepts, and help with exercises.
Instructors and students get to know each other.
Instructors encourage students to keep up with readings and exercises.
Skilling helps instructors monitor students, and contact them personally.
Instructors assess student performance, with exams, projects...
The grading system makes assessment fast and consistent.