To give a bit more data: in my other life (ie. not as a beekeeper) I have a Masters in Adult Education. Which is to say – I understand a bit on “how people learn”.
Only about 40% of the population learns by reading (Auditory Learners – since reading is based more on the brain centers with hearing than vision). This is the portion of your audience that writing documentation will help.
Another 40% of the population learns by seeing (Visual Learners). This is where a video can really help. You’ll essentially double your market by doing videos.
The other 20% learn kinestheticly (by touching). Unless you’re willing to sit with them as they do things, it’s hard to reach this segment.