[jurialmunkey]

But animated backgrounds should be doable with gifs in gui already no? I mean we support gifs in images and its the same control afaik?

Unfortunately no, not Animated GIFs, not even under the Pictures section in Kodi because Animated GIFs are displayed as still images and not played as videos. At least not afaik?

Animated gifs are definitely possible - I use them in both eminence and arctic zephyr (1.0.9 onwards) for loading indicators. Apparently gifs are better than using looped rotate animations on low powered devices like RPis as they use less cpu cycles to render.
Kodi can be a bit picky about which gifs work - I usually have to import them into gimp and then export them back out with "replace frame disposal" for all frames to make sure they work properly,, but they definitely work.