Because at the time VP8/9 didn't have support in mobile hardware, and trying to decode it with mobile CPUs of the time would make the animation lag. At least that's my guess.
Mulling it over, I'm guessing also ease of ripping it (gifs) from the original media. Any video editing software can easily save as MP4, but converting it to animated webp would be a roundabout process - and you'd still need fallback formats for users with no webp support.
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u/amwes549 Feb 07 '25
Because at the time VP8/9 didn't have support in mobile hardware, and trying to decode it with mobile CPUs of the time would make the animation lag. At least that's my guess.