> It's not a law of nature that hypermedia should exist only in the context of browsers
It is sort of a law of hypermedia that different resources are different files, though, isn't it? I guess you could make a file format that embeds images and fonts and HTML in it, but why bother when we have PDF?
PDF is a print format that evolved to support some modern features like links, forms, etc, but at its heart, it's still a fixed-layout document, and I think having a responsive static multimedia document is a massive advantage in a world dominated by heterogeneous devices
