For mechanical stuff (dis/reasembling equipment) it makes some sense, because diagrams are never as good as an HD video at showing where that screw hole is or how to pop off a clip. At the same time, I can't watch most of those videos at less than 1.5x!

Often, the first google hit on "how to do X" is a video when, as you say, a bulleted list would be easier to follow. Maybe ads are better monetized on video so the incentive is only to create that content?