Video essays are basically what they sound like. A content creator has a thesis that they want to inform, persuade, and/or entertain about and they write up said essay and read it into a microphone. Then begins the arduous work of assembling stock footage and graphs to support whatever they were talking about. Finish it out with some clips for quotes and you are done. Post it to your video hosting site of choice and watch the ad revenue dribble in. While there is a lot to be said for the humble blog, the sheer volume of users combine with intense matching of interest by the algorithm offers an excellent effort to reward ratio for people who are serious about carving out a niche.
At the next level of video essay we have actually good graphs that really add in understanding and photos that help people track names by attaching them to faces. Stock footage still fills the interstitial moments but they're fewer and further between. Toward the far end of quality graphics contain around half of the information and there is no wasted space. This is most apparent in math and physics explanations that are able to provide visual expressions of highly abstract concepts. See 3Blue1Brown for examples of this.
Video essays are a product of their communication medium. While they are effective at informing, persuading, or entertaining for many topics they are overkill and for others hands on experience and toy models serve as way better pedagogic tools. That said, the format is likely to stick around for a long time since present distribution models prefer them and most of them double as a podcast.
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