I don't think the size is a key advantage here, even if it were true. 96 kilobytes simply isn't very big to start with, considering most of the content that gets sent around.

Like you said, support is what matters. SVG is notoriously difficult to implement and it took forever to be supported everywhere, which also contributed to the persistence of Flash. TVG is supposed to be easy to implement, which seems to be to be the advantage.

JPEG, by contrast, is a pretty simple format with only a few minor quirks.