SVG Animation (based on SMIL) and CSS Animation offer some similar features for animating Web content. Harmonising these two technologies has been considered on a number of occasions but a path forward has yet to be established. In response to a feature-by-feature comparison of the two technologies the question was raised, “What are the animation features required, prioritised by use case?” (Meeting minutes which lead to Action-48) although a closely related question was, “What would it take to make CSS Animations achieve feature parity with SVG Animations?”
From face-to-face meeting on Web Animations, as discussed here. There is now a CSS-SVG Effects Task Force activity on this.
It has taken time, but by now CSS and SVG are on the same team, which is kind of a precursor to make the specifications well-integrated as well.
I’d like to see proper animation support in SVG as a background across browsers including JS based animations.
When I was involved my opinion was that backgrounds could be animated but not interactive (interactivity solely for foreground items). One of the earliest regression bugs in the older bts was that background gifs didn’t animate, and they should. The actual technology for animation should be (almost) immaterial. File bugs where you see them.