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?).
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.
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?).