The best developers aren't putting out tons of content or courses. The people putting out popular courses are just the best course developers/marketers. There are plenty of folks like Tom Christie, who has minimal social media following, but who built Django Rest Framework, which is used by tens of thousands of projects. The best developers are leaders, whether or not they're thought leaders.
I remember reading the iWoz book by Steve Wozniak. At the end he had some advice and one thing he said went against all popular advice but sort of agreed with my internal dialog. It was basically "work alone". EDIT: "Artists work best alone. Work alone."
What has happened to all the introverts who work alone? They're not working in tech. Tech is for extroverts who get paid to copy from public GitHub repositories and paste into private GitHub repositories and sell proprietary products built upon code ripped from open source projects.
But that's okay. Not everybody can be an extrovert who gets paid to pretend to code. RMS said it best:
> I could answer that nobody is forced to be a programmer. Most of us cannot manage to get any money for standing on the street and making faces. But we are not, as a result, condemned to spend our lives standing on the street making faces, and starving. We do something else.
And then RMS was railroaded out of the free software movement he started by the social extroverts who replaced all the introverts in tech.
I'm an introvert. I'm a coder. I don't get paid to code. I do something else.