To add to that, text has more of "authorial intent" (debates on the demise of which notwithstanding) than other media.
Consider the visual rebus, for example, which is open to interpretation and depends on commonality of context in both producer and consumer, contrasted to a rigorous argument, which depends onoy on commonality of (technical) jargon.
Video ends up conveying information thanks to narration, while the visuals assuage boredom. Like an Adam Curtis documentary: it's essentially an essay read out, with clips and music overlaid to keep the audience from realising they're told, rather than shown, the argument.
Having the talking points as aides memoire on screen is nice in that it charts the course of the argument, but the map is not the territory, and we end up with significant information loss and knowledge gap.
I think that moving from the message in itself to its summation (i.e. from text to bullets) creates a knowledge divide between the producer (who knows more) to the consumer (who has access to less and can only divine the rest).