For most of my writing (journal entries, notes), I have never needed the collapsible subheading and export functionality because I write primarily for myself. If I think a note is ready to be published on my blog, I will still rewrite, edit, and polish it in a separate file. Mostly also in Markdown, because the structure of such articles does not go very deep (I am not a fan of many levels of headings) and my static site generator handles the export to HTML in a fully automated way. No need to export anything manually.