It's probably fair to say that trends towards entirely digital music learning are a direct threat to virtuosity, regional style and instrument and technical diversity built up over millenia. Meanwhile, ethnic/niche-instrument musicians and their learners worldwide are consigned to the vagueries of video chat.
What, in your experience (moderators: read "expertise"), are the main impediments to learning (moderators: read "facts") online using video chat?
No rants or discussion, please: just state the problem and (if relevant) the supporting environment (moderators: read "references"). Always check to see if your answer has already been given, and vote up answers you agree with.
Again. Vote up rather than repeat!