""" In my idealistic vision of how scientific publishing should work, each paper would be accompanied by a fully interactive environment where the reader could explore the data, rerun the experiments, tweak the parameters, and see how the results changed. """
I do like seeing larger labs/companies releasing research full of SVGs. In recent memory, I quite liked this from NVIDIA:
For example, I once adjusted an Object Pascal interactive program (target: Windows/Win32) for the browser target (FreePascal compiler has the JS target). An intermediate result was a bunch of files that worked locally on desktop but struggled on mobile. With a little help from the SingleFile extension [2], I ended up with a single HTML file containing all functionality and content. It worked great, for example, in MiXplorer's internal HTML viewer. I can't recall the exact details, but the file:/// protocol still had issues in Chrome, Firefox, or both. Anyway, preparing a local address correctly with a keyboard is a challenge so let's just assume that having capable file managers running local html files is enough
Sure, to make this manageable, you need good tools that handle all sides of the task. But at least in theory, the format is fully capable. My only global issue was that the state for locally run HTML files is a kind of ephemeral entity, but for interactive multimedia files, you may consider this obstacle small.
It's if we had the .docx format but MS Word was read-only. You would have to create the XML and zip it yourself, to be then rendered by Word. That's effectively how I see HTML+js in browsers.