Reminds me of Pascal's quote of not having the time to write a shorter letter.
As a some-time presenter myself, and having the typical introverted personality (including slow speech due to all the thought processes going on to calculate the right way to say something), I have found that it takes quite a while to prepare a good presentation (non-boring and engaging, let alone one that the audience can learn something from). I would say at least 8 hours for a 40-minute presentation, but that is after some experience already. Longer gives me more time to prepare better.
I have seen quite a few tutorials and presentations where it seems the presenter hasn't spent much time planning the presentation through. First run through gets recorded and uploaded without too much editing either. To the point that I only watch a video to learn something as a last resort.
Other problem is of course in areas with buggy network connectivity, or very basic connectivity like much of the third world, video is all but impossible to use.