Before I renovated my house, I might have agreed with you. But leaning building, carpentry and plumbing by watching is by far better than reading.
You need to write, edit, and proofread the content, while you can just speak as you go while shooting a video.
You need to sort through a ton of photos and annotate them, while you can do with a worse quality video, because the motion helps perceive the details in imperfect conditions, and annotate much of it by voice?
Some tricky parts of repairing stuff can be more easily shown in a 20-sec video clip than by 15 well-made annotated photos, the latter taking way more time.
I think for certain areas, like the electronic repair stuff, video may be not just the most adequate medium we have, but also the fastest and easiest-to-produce medium.
>you can just speak as you go while shooting a video
You're comparing a "good blog post" with a unscrippted/uneddited "video log".
It's not the same - it's comparing Louis Rossmann VS iFixit. One is a form of educational entertainment, or entertainment, other it's a guide. You can learn from L.R., but it's not a step by step guide.
You don't need to go back and try to find time stamps, you don't have issues of not understanding something that got muffled by him moving, you can miss a reference, etc.
If you're talking about video guides, then they are scripted and will for sure be harder to edit than a blog post.
There's a place for everything, and production costs (SHOULD) reflect on quality - the medium is irrelevant.