[robonerd]

> YouTube is perfect for 10 minutes of content without having to try to stretch it to an hour.

10 minutes has no relation to the complexity of the subject matter; 10 minutes is derived from the attention span of youtube viewers (and it varies a bit, but sub-15 seems to be the most common). An hour of content may be pruned until only 10 minutes are left, or two minutes of content may be stretched to 10.

Example chosen from the videos they're recommending to me now: Two documentaries from the same channel. One is about the Bob Semple tank, a wacky prototype from New Zealand designed by an amateur and never mass produced and never used. The other is about the 1960 U-2 spyplane shootdown over the Soviet Union, a serious diplomatic incident. One is 9:08 long, the other is 9:20 seconds long. What are the odds that both subjects just happen to have almost exactly the same amount of content to say about them?

Zero chance of that. Compare the articles on wikipedia, the U-2 shootdown article is 5x longer than the article for the tank. The two documentaries are the same length because this guy always makes his documentaries roughly this length because this is what the system rewards.