GIF [Graphics Interchange Format] was getting obsolete - people were starting to use PNG images and proper videos for things that were done with GIFs. But the meteoric rise in computing horsepower coupled with an equally staggering rise in Internet downloading speeds has given a second life to the GIF format. Heavy GIFs are no longer a problem - they get downloaded in the blink of an eye, and the graphics/processing firepower renders them smoothly without breaking a sweat. Anyone who has interacted with both GIFs and videos on the Internet knows that the lag associated with GIFs is much lower than that with videos proper. GIFs render and play as quickly as regular JPEG or PNG images - there's practically zero overhead associated with them.
The rebirth is fascinating!