Video is a high-bandwidth way of delivering information at a low bandwidth. But try watching tech videos at 1.5 speed, it makes them much more engaging. Also works for ponderous anime.
Hah! Ponderous anime. I remember watching some shows at 4x speed. I'm not sure whether it's anime that introduced me to sped up video, but subtitles are a great help when watching videos at faster than 1x speed.
That's why I prefer youtube over the other services - you can speed it up. I'm not a native speaker, so 1.25 is the fastest I can understand at the moment.