As I understand it, LJ gave another developer his blessing to take a stab at Sync for iOS (I imagine with some sort of financial arrangement) but development had been very slow, and it never left TestFlight.
Furthermore, apps using the unicode versions of functions (which all apps should be doing for a couple decades now) have 32kb maximum character length paths.
Thingiverse was stagnant and underdeveloped for many years and borderline unusable at times, so a lot of people feel pretty strongly about migrating to other sites.
Microsoft is adding extensive archive format support (using libarchive) to Windows 11. I'd like to thank 7-zip for its service over the decades, though.
What people call GIFs these days are almost always not actually GIFs. GIFs will usually have high dithering due to it using an 8-bit color palette and an odd frame rate because the per-frame delay is specified in jiffies so you can't really get normal framerates (especially high ones).
What dethroned GIFs was the <video> HTML element. The video format doesn't matter.
Fun little side fact. That first video with the Shining parody is what inspired VSauce to start making YouTube videos.