I personally make educational videos, but that's not what dominates on YouTube :-)
> I do not believe video will come to dominate such that text and audio won't still have a place.
They will have a place, for sure. Podcasts are still rising in popularity - they're a great platform for transferring knowledge and value and also debating.
> I personally can't get much out of most non-fiction videos, and I know I'm not alone.
People learn in different ways. Most people are visual, however, and video/interaction/workshops are the most popular means of learning for an incredibly large portion of the population. Source: married to a teacher.