As with stills, there is good video, and bad video. It's a matter of quality of the product, both technical, and content-wise. It is just another means of conveying a story, of telling a story. Content is of the utmost importance.
As for having to watch it to the end, that is rubbish, one can skip along quite quickly, once the quality of the content becomes obvious, or it turns out that it is not that interesting after all:)
Also, sometimes it is a lot easier to film a procedure, than trying to describe it with words. Makes things more understandable.