The common trend in educational videos is very interesting. The videos that are made approximately from 2-10 minute long with animation and pictures are very easy to follow than to watch hour long stanford or mit live class room recordings.
Often, though, hour long lectures is the only way to go. You just can't learn much in 10 minutes with an animated video. Sometimes you just got to delve in.
I think watching something like this before watching a deep dive or reading a text book could be useful, just to give you kind of a lay of the land and some intuition.
I disagree very rarely does one explanation take that long. It can normally be built up by lots of little videos. Once someone has completely 10 videos on the basics you can do slightly longer ones that span the concepts and explains tradeoffs between techniques.
I feel that the hidden trick to the live classroom recordings is to watch at 2x-4x speed and rewind and go back to 1x the moment you don't understand something or if you are explicitly following a worked example (even then I usually cruise at 2x). If you have pause you can just work at a different pace.
If you don't mind the chipmunk-voices, that could work :)
You can speed up Youtube to 2x by clicking on the settings button in the bottom right (4x sounds insane to me). And there is no chipmunk effect.