Markdown is a bit limited (the spec doesn’t cover common extensions like tables of contents, internal links, and explicit page breaks). AsciiDoc is better on that issue.
The only use case I have for being picky about the formatting/layout of a document is my resume. Some people have a threshold for how long a resume is allowed to be (for example 1 additional page per 10 years of experience). Also, I have all of the dates right justified (for easy skimming) but still on the same line as the job title (to save space on the page).