Yes, in ancient history, video codecs sucked, browsers sucked, and the only way to play video was through plugins that sucked.
Now, all the browsers are pretty good at dealing with video, the codecs are hugely improved (although, there's some headaches with IP) and the plugin is dead.
Nobody ever actually wanted gifs. They want short, small videos that are guaranteed to work in their browser and that they can be pretty sure aren't going to have sound. We can now deliver that.
To be fair: they don't want short, small videos any more than they specifically wanted gifs.
They want moving images that load quickly. Which has meant short/small/gifs, because most US bandwidth still sucks. And thanks to the mobile explosion it now means short/small/h264.
But I bet that as people become used to 5-10x space savings from h264, they'll quickly respond with videos having 5-10x more data. (larger/longer/higher-res clips)
In ancient times before plugins, animated gifs or any sort of video, we would painstakingly screen cap individual frames from movie clips and use "push" via CGI to force feed the browser a series of images that gave the illusion of animation. It was just a hi-tech spin on flip cards.
Now, all the browsers are pretty good at dealing with video, the codecs are hugely improved (although, there's some headaches with IP) and the plugin is dead.
Nobody ever actually wanted gifs. They want short, small videos that are guaranteed to work in their browser and that they can be pretty sure aren't going to have sound. We can now deliver that.