Despite the code-heavy approach of most of these libraries, it's actually incredibly easy to define custom HTML elements and there's nothing to stop us writing tags that give authors a clean declarative way to express their content. That's how I approach things on this site, and it lets me easily add rich media as inline HTML to my Markdown posts.
<x-map> <x-location latitude="35.671336" longitude="139.702941"> Harajuku Station </x-location> <x-location latitude="37.766655" longitude="-122.418129"> 1515 15th St </x-location> </x-map>
<x-model src="model.stl" />
<x-chart type="pie" legend="bottom"> <x-chart-labels data-values="January, February, March, April, May, June, July"> </x-chart-labels> <x-chart-dataset data-values="12,19,3,3,5,2,3"> </x-chart-dataset> </x-chart>
all with relative ease.
None of these represent perfection in their HTML tag design (they're very much a first-cut), but they allow me to author this website quickly and easily, and demonstrate that we don't need overly complex platforms or editing tools.
I would love to see library authors offer HTML extensions as part of their frameworks to really reduce the barrier-to-entry. It would also provide a wonderful oportunity to explore the possibility of future HTML tags--I don't closely follow the HTML standards bodies, so I don't know this to be true, but I have a sense that we've all-but given up on simple user-editable markup at a time when it is perhaps easiest to achieve.
If you'd like to use the chart support in your own sites, you're welcome to check it out on GitHub. It's very much a first draft, so your mileage may vary, but I'd love input and help developing it.