Why do we not have rich text code yet? Headings could be large. We could embed diagrams with graphvis or mermaid. We could hyperlink and have tables of contents

Why do we not have rich text code yet? Headings could be large. We could embed diagrams with graphvis or mermaid. We could hyperlink and have tables of contents or even embedded runnable forms like a Jupyter notebook. Comment anchors and similar are close though. https://marketplace.visualstudio.com/items?itemName=ExodiusStudios.comment-anchors https://marketplace.visualstudio.com/items?itemName=ExodiusS...