Gotta love online learning...no more waiting for information to be available in a text book and to enroll in classes to get educated.
I am not saying that this guy does a bad job but, in general, I avoid videos like plague after many bad experiences with them. Especially those where there is just scrolling text and some god awful soundtrack with it.
Firstly, nothing. No one said there was.
Secondly, from what I can tell, writing is inferior to the human physical expression, which includes speech. It exists to mimic and preserve thought or speech. But it can never be precise, simply because the human body augments speech. When writing gets close to accurately doing that, it become verbose and tedious.
Or, to put it another way: Would your kids prefer to read or be read to? Would you prefer the lyrics or the song? The script or the movie? You might, most wouldn't.
Atleast in the current context, books are faster to reread compared to rewinding a video, which can break your flow.
OTOH speech conveys emotion better and feels like it has less mental overhead to consume and produce. I know a few people who are excellent speakers but very poor writers for example.
Most people--even us self-motivated HN people--are far more likely to do hundreds of hours of coursework if there's a real class, human teachers, and other students than if it's online to pursue at your leisure, or in a book sitting on your shelf for that matter.
The overwhelming majority of my formal education (through high school and most of college) consisted of classes where most of the students either didn't want to be there, or weren't interested in the course beyond its impact on their grade and future transcript, and so were disruptive to the learning process.
And I doubt I'm alone in saying that.
Of course the latter isn't perfect and comes with its own evil hegemony and other assorted issues, but the point is that there is so little barrier to entry to posting on the web that praising speed in and of itself ignores relevant and important issues.