I'm still disappointed that you can't use (silent) videos in <img> tags or CSS properties where you can use images. Animated webp is so much less efficient than webm its not even funny. There are many places where you can already embed images (including GIF and animated WEBP) but video is not supported or has other restrictions.
But you can already do that. AVIF animations are regular AV1 videos. There is zero end user visible difference between what the above user is proposing and what AVIF does. Allowing webm in img tags would be identical.
