The author is also a Sanity employee and, while I like the ideas behind the Sanity CMS, if you ever create a schema with an RTF field, you'll see the opposite extreme when you read the text back via GraphQL. If Markdown was created to make the source readable, Sanity exists to make content unreadable (via expansive nested JSON for even simple tags like <b>). It's pretty easy for a paragraph of text to take 200 lines of Sanity JSON.
Like Sanity, this author has expanded three paragraphs of content into 600 lines of text. I'm an avid reader but that doesn't mean I want to reread the same reworded premise over and over.