The look of the text is just the tip of the iceberg. Many text editing operations are tightly integrated with the operating system and impossible to implement

The look of the text is just the tip of the iceberg. Many text editing operations are tightly integrated with the operating system and impossible to implement without an editable element. For example, on recent iPads you can move the cursor around by swiping the keyboard with two fingers. I don't know how you'd support this gesture without creating an actual editable element on the page.