I agree that what students do outside the classroom is as important, if not more important, than the lectures. However, going through the lectures, in person or through a video, lessens the learning curve for critical skills that are a prerequisite to outside the classroom learning experiences. In other words, these videos give everyone who watches them an opportunity to engage in the next level of learning.
I believe it is possible that with these prerequisites moved outside of universities, it becomes possible for more group learning experiences, not unlike those you experienced with professors and other students, to become available to everyone. Currently, the latter is only available (mostly) to students at a university.
People don't (read: shouldn't) think that all it takes to become a computer scientist or civil engineer is to watch a few videos. They definitely know that they can't without learning the concepts in those videos, allowing themselves to become more involved with real challenges in the field and further their educations.