Professors can post handouts, course materials and interactive programs so students can do quizzes and get instant feedback from the computer. The trick is doing all this without classroom meetings. Some feedback can be handled by sophisticated software, but such software is expensive to buy and use. You may be noticing that good online teaching is labor-intensive, and works better for smaller classes. So much for saving money.
Surveys suggest that it depends on the students, the course, the teacher, the weather, etc.
The only clear result is that student evaluations of distance courses tend to be lower. And many administrators are still fantasizing about recording lectures and doing without faculty. Indeed, the gullibility of administrators is becoming legend. One recurring true story is of a slick salesman who sells expensive software to an over-clever administrator who did not rely on faculty input. The software turns out to be useless.