However, as a professor myself in a rapidly evolving STEM field adjacent to AI, I update at least 20% of my course materials each year to keep pace with new developments. As it happens, about a third of the new content is derived from my research group's latest work. Recording lectures isn't a one-time effort; it would require constant updates to remain relevant (and let me tell you, if you want to get the voice-over right, it is a lot more time-consuming and soul-crushing than simply turning up in class and giving a live lecture).
The value of live lectures goes beyond just "transmitting" content. They offer real-time interaction, immediate feedback, and dynamic discussions that adapt to the students' understanding. This level of interaction devilishly difficult to replicate in recorded formats.
I would ramble on more, but I need to return to the lecture materials I am developing for this Friday on Vision-Language Models :P