Let me discuss two aspects of a good course that are most important to the student: Content, and Learning. There are others, of course, but I'll leave them out of this discussion.
I don't think that content and learning are independent, but they are quite different things. So, if you are asking if improving the content of a course would help improve a course, then sure, it would. But I think only at the margins.
But learning is much more than content. If it were only content, then you could go to the university bookstore, purchase 15 or so books and then carry them to the registrar's office to collect your MS degree. Um, no, I don't think it works that way.
Perhaps you are confusing education with entertainment, at least a bit. If you listen to a brilliant lecturer speak, in a classroom or (more likely) at a conference, you won't really learn a lot beyond what it will be important for you to study. It is the study, not the content or the brilliance that will result in learning.
For learning to occur the student needs to do a lot of work, solving problems, writing, getting and evaluating feedback. Then, more problems, feedback, etc.. Eventually some insight will emerge, we hope from the hard work. Learning involves changing the brain and developing long term memory and connections between ideas. Content alone, even brilliant content won't do that. Only hard work, usually involving repetition will.
Perhaps I'm a case in point. I'm probably just an average professor and I worked at mostly just average universities. But my students learned a lot and some of them have gone on to surpass me, getting their own doctorates and now teaching at top universities. Some others became leaders in industry and government. But I never relied on fancy videos. I just made them work hard on meaningful things and gave them a lot of feedback. I also let them improve on their mistakes by resubmitting old work. How the content was delivered mattered much less.
And, of course, you can't interrupt a video lecturer to ask them a question. So, if you miss some point, you are just stuck until the video ends (assuming it is delivered in a classroom situation, rather than offline in a "flipped" classroom). And then you get farther and farther behind the presenters ideas.
My philosophy of teaching is that it matters much less what I do in the classroom than what the students do. So, course design starts with the exercises and projects that the students will do to actually learn. Over the years I came to rely much less on lecture and much more on reinforcement of key ideas (not presentation, reinforcement).
But, I didn't always think that way, sadly. At one time I developed the absolutely perfect way to teach (hmmm, lecture on) statistical sampling. I created the absolutely perfect lecture. When I delivered it, brilliantly, I think, I noted that only about 5% of the students actually understood what I was talking about. OOPS..
On the other hand, I've had the experience, teach math and/or cs, as have many others, that when I stumble through a lecture and have to figure it out as I go along, backing up and moving forward.... that the students afterwards thank me for giving such a nice lecture. That is because that stumbling is how they often have to work and seeing a prof stuck in the same way is both reassuring and shows them how the "smart folks" really work.
And note, of course, that great content already exists. Great learning and great teaching is another thing altogether. And don't denigrate the "average" professor or the "average" university. A lot of deep learning goes on there. Likewise a lot of really incompetent people graduate from top schools. I've met some of them and some of them are public figures.