It's interactive, for starters. You can do that with SVG, of course, but the boilerplate required would be larger than the `.canvas` file. You can externalize the boilerplate, but then you're no longer creating portable SVG files, and if we're going to create an SVG-like DSL we may as well try out this JSON-like DSL.
This isn't obvious to me. You can have javascript external to the svg for making it interactive, it doesn't have to be embedded in the svg. And the interactivity for json canvas isn't embedded in the canvas json either.
Interactive like this? https://yqnn.github.io/svg-path-editor/
I still don't see your point. Why wouldn't I always choose SVG? What problem or pain point is being solved?