Feynman was brilliant, and I have a set of both his lectures for freshman and the ones he did on gravitation. But he was not a gifted teacher. He was a gifted learner. Those of us who can follow him can see an amazing mind at work. But gifted teachers will look into students minds and help them build new understandings.
But that's just my point: there is no 0 to 100 scale of 'goodness' in teaching. And Feyman, regardless of his brilliance, doesn't sit at the top of hierarchy of teaching excellence. It's about fit between the student and the delivery the instructor. The Feynman lectures in video form can not be the pinnacle of physics instruction because they're fixed, not adaptable to the needs of different learners.
You said "his teaching can be highly effective when matched to the proper audience." I disagree. He famously could teach extremely effectively to any level of audience.
You said Feynman "doesn't sit at the top of hierarchy of teaching excellence." Many people would disagree. Many people consider him the greatest physics teacher ever.
In terms of just the Feynman lectures in video form, Yes, I agree that they are limited. But I brought up Feynman because I believe a feynman caliber instructor alive today with the existing possibilities in software and video would definitely be able to make something very adaptable to many learners and easily more effective than the average teacher.