The writer can work with headings, lists, quotes, emphasis and images without making the underlying text dependent on a proprietary visual document format.
The editor optimizes the act of writing
Formatting should be visible and convenient. Writers should not have to think in markup syntax during every paragraph unless they want to.
Portable text optimizes longevity
Markdown is comparatively simple, inspectable and export-friendly. It reduces the distance between “my text” and “the application’s internal representation of my text”.

Comfort and portability are not opposites
A local-first tool can provide a modern editing surface while still treating text as something the project should be able to carry, transform and export cleanly.
Why local-first? · Focus Mode vs Split View · Why export one section?