Weird that I’d say almost exactly the opposite. 1-1 speaking is one of the slowest forms of communication today.

Writing copy is 1-many and the many readers can read much faster than they can listen.

Making a demo video is also 1-many and can be sped up (who doesn’t listen to content at at least 1.2x these days?).

I agree with you IRT scale but not speed.

Copy and demo videos are essentially one way communication channels ("fire and forget"). The creator has no idea if the message was understood.

Also, writing copy or making a video typically takes 10 - 100x longer than consuming the same video.