https://mediacru.sh/ was on the front page a day or so ago, it grabs GIFs and re-encodes them into video (MP4 and OGGv). The results are much smaller and, in my local experimentation, are much, much faster to render than the original files.
The gif loaded and played seamlessly. The video was a placeholder which loaded a full screen QuickTime window that delayed for 5-10 seconds then played.
Claim "gifs are still the simplest way to show short video clips on the web." agreed.
There's some technical details at https://mediacru.sh/demo .
Draw your own conclusions, but that's how I have experienced it.