We are stuck in the old paradigm of characters taking space on the screen and the idea that a markup language must support classic dumb TUI. If, just imagine it, we used some Unicode range for control characters for the semantic markup and standardized UX for it, we wouldn’t need using normal characters as delimiters and escaping them in strings.

The following would have parseable structure, but would be free of visual noise.

  Title: Markup languages: decades of going in the wrong direction 
  Keywords: hypertext,
      delimiters, 
            ˋ, ", \

People have suggested using the control characters for CSV structured files. The problem is that they are impossible to edit.

Control characters are invisible, using them means changing text editors to display them. They are also, outside the usual ones, hard to type. ASCII ones have Ctrl combos, but editors used those for other things.

Also, what is the difference between using some new character to start block and "{" or "\n"? Why have new thing to indicate new level when have space and tab?