It was really hard to write - took me 1.5 years, tons of research and re-writing. This isn't something I slapped together over a weekend. Far from passive income.
Creating content for me is always hard, but once it's done, I love to deliver it (via talks, teaching, videos or books...)
I tried to write blogs and had to write papers for university, but I always struggle.
I have the feeling that some people can produce much text from nothing, where I put my ideas into a few sentences...