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.
A video has sound, can be exported from the animation software to a single file, and it can be played in a standard video player.
Animated SVG does not sound like it does that, and needing new paid* software isn’t great for adoption either. And honestly, I’ve never even heard of animated SVG (I’m well aware of SVG and that it probably could be animated with CSS or JS but that alone does not make it a thing).
The fact that vector works at resolutions (even if they don’t exist yet!) without the author even needing to think about it (let alone re-export) is an advantage. It can be great for many 2D aesthetics (many cartoons even used it!), the biggest complication is Adobe (and whoever is selling a subscription to what you mentioned).
Also that people are still developing things with Flash (even if it has to be ran via Ruffle) tells me again that the issue isn’t vector, it’s that replacing a format with ingredients is not an effective strategy if you actually want people to use it.
* yeah I know Flash was expensive as well (except y’know… other ways), but communities were already using it