The thing that really annoys me most about that terrible post about tumblr converting GIFs to mp4s is that the quality loss isn’t from the conversion of GIF to mp4 is when you took the h264/h265 video you started with, and turned it into a GIF!
If I could just upload the mpeg4 video or a webp file as an animated image to begin with, there would be so MUCH less loss in quality!