If this shows itself to be highly useful as a concept, then I would perhaps avoid reinventing the wheel on the file format side of things, and just standardize what we already have:

- Come up with a file extension (.hmml)

- Decide on an entrypoint filename and format (index.html)

- Use an existing standard for combining resources into one file (tar + zstd)

Now you have something that is usable only using pre-existing tools.

Yeah I agree

in fact this is both a packing strategy or a POV of thinking. Next browser versions could support it.

<img src="html-underdog.hmml" />

or

when tomorrow's genai models mix declarative images with rasters, then they would like something like this

or

OS -> html-underdog.html double clicks -> browser opens it.