I was thinking the same thing. From what I can tell though, animated gifs are more popular than ever. What they lack in image quality and compression, they make up in convenience... And having no sound is actually a feature. I'm sure there's a lesson to be learned here somewhere...
And, at least for my Chrome, a lack of hardware acceleration. It nearly freezed trying to play the three gigantic (and resized to boot) GIFs. I don't want to try that site on my smartphone.
GIF decoding has never been hardware-accelerated (as HWA is commonly used in this context, using fixed-function units on silicon taking care of computationally expensive parts of decoding). We (as in the Internet) were laughing at dancing_baby.gif (among all the other GIFs that Geocities page had at the same document) back in 1997 played back on Pentium 2 CPUs.
And animated GIFs are just a bunch of frames indexed with 8bit color, all packed with LZW. It's no h264 to require hardware acceleration and even the latter can be decoded effortlessly without accelearation by modern CPUs.
