Some of you might remember when a 3mb flash animation could pack in some 5 minutes of animation, with the more advanced ones even having chapter/scene selectors, which could also include clickable easter eggs and other kinds of interactions during the scenes.
Interactive Vector Animations as a web standard are technically possible, but it’d be best implemented as animation software that compiles a file/archive that’s usable by a standard browser based client that renders things locally using a canvas element.
In-fact its so possible flash has been re-impmenented this way using an action script interpreter compiled to web assembly.
They didn’t give you the entire kit because that wasn’t the W3C’s job, it was to give you the tools necessary to build the kit.