Good news! We do have those primitives! The canvas element can - and is - used for drawing, and input events are fairly easy to manage. Larger projects like Google Docs or Figma often go in this direction, because for very complicated applications, it's useful to be able to handle every part of the rendering process yourself.

That said, it turns out having a rich selection of easily-debuggable, accessible components attached to a powerful layout engine is also really useful, hence why people mostly stick to the DOM unless they specifically need something that only canvas can offer.