That's one of the higher leverage activities for an instructor. Anyone can go read a book, watch a video, or do some practice problems, and lecturing at a bunch of students isn't a great way to convey information, either in absolute terms or compared to those alternatives. The instructor's job is to tell you which books to read, why the material matters, and contextualize the course against other things you care about. The particular road they tell you to travel depends on where you currently are, and a 2-way conversation is critical to getting good results.
That's one of the higher leverage activities for an instructor. Anyone can go read a book, watch a video, or do some practice problems, and lecturing at a bunch of students isn't a great way to convey information, either in absolute terms or compared to those alternatives. The instructor's job is to tell you which books to read, why the material matters, and contextualize the course against other things you care about. The particular road they tell you to travel depends on where you currently are, and a 2-way conversation is critical to getting good results.