I've updated by Hugo based editor to try and use EditorJS as, well, the editor for the blog.
Workspace in classic editors is made of a single contenteditable element, used to create different HTML markups. Editor.js workspace consists of separate Blocks: paragraphs, headings, images, lists, quotes, etc. Each of them is an independent contenteditable element (or more complex structure) provided by Plugin and united by Editor's Core.
I think it works.
I struggled a little bit with the codebase, the examples all use ES Modules, however the NPM dist is all output in IIFE ES5 code. But once I got over that hurdle it has been quite easy to build a UI that looks a bit more like medium.