> People who have the knowledge and want to capitalise on it are highly incentivised to preparing beginner level materials and maybe a tiny bit to prepare the something for people who already have a bit of knowledge. After that, the number of people who are your potential target drops off sharply and you would have to increase the price dramatically.
I think, even aside from the incentives, its a matter of interest and time. Earlier in my career, when I was learning at a rapid pace, I also had the time and motivation to write blog posts about what I discovered, as did many of my peers. Its also easier to write about beginner concepts, because they're simpler.
As I've advanced in my career, the things I'm learning and doing are more and more complicated, and/or require much more prerequisite knowledge. Not only do I have less time, there's also a corresponding increase in difficulty in writing concisely and coherently about the more advanced concepts.
About once a week I read a blog post in a field I'm familiar with, and recognize it as something I myself would have written 10 years ago. But I also now see in it the potential problems and pitfalls, and tweaks to make to avoid them. I think to myself "I should write a blog post about that", and sometimes even jot down some notes or a draft, but the topic is just so complicated, and the potential problems so subtle, that it takes a large amount of effort just organizing it, and I get bored/distracted and move on, never finishing it.
Talking to those same peers now, they feel much the same. And even with the experts that do manage to write about expert topics, that's become their full time job. Then after a few years of full-time writing instead of full-time doing, I find when they write about a topic that I've been full-time doing while they were writing, there's gaps in their knowledge or new techniques and tradeoffs they've missed.
I don't know how to solve this problem, except maybe figure out a way to give the knowledgeable experts a sabbatical or something, where they can take a break and write. Good luck getting a startup to agree to that, though.