SVG feels like a very underexplored and underused territory. You can do so many things with it. It really depends on your imagination. But you’ll possibly need to “hardcore” a lot of stuff, so yeah, depends on the use case as well.
Browsers will render SVG files. SVG files can link to other SVG files. Just need to configure the server to serve SVG by default — most servers don't but it's an easy config change.
I've used SVG in the past to work around limitations in css alignment (cloth before and after new layouts made it unnecessary--I don't write CSS enough to remember how they work, but adding text to a quick drawing in inkscape is fairly trivial)