An uninterruptable lecture is almost as much an abomination as a TV broadcast, but even a replayable recording is no better than a bad lecture – where the only response to a question is to repeat verbatim whatever was not understood.
The point of a lecture is to allow spontaneous rephrasing or elaboration to correct for misinterpretations. In the absence of that you might as well use a book or printed notes, since written information is both much easier to navigate and much quicker to take in than that which is spoken.
I am reminded of my fury in the early 70’s when a fad for audiotape seemed to sweep across North American Biology departments and students who had missed a lecture were forced to sit and listen to it through headphones rather than having decent written notes provided.
Certainly there is a place for audio as an appropriate means for conveying verbal information when visual attention is required for something else like a picture, or animation, or manipulative activity, but for the bulk of a videotaped lecture the video is completely wasted.
Of course, there is one advantage that recorded speech or video has over text and that is the inclusion of affect as part of the message, with the possibility that retention may be enhanced by an empathetic response to the speaker. But in most cases these are enhanced by immediate proximity – which is why live theatre survives and why a live formal lecture is only almost as bad as a TV broadcast.