

I take that there isn’t much motivation in moving to 128 because it’s big enough; it’s only 8 cycles (?) to fill a 512 (that can’t be right?).
8 cycles would be an eternity on a modern CPU, they can achieve multiple register sized loads per cycle.
If we do see a CPU with 128 bit addresses anytime soon, it’ll be something like CHERI, where the extra bits are used for flags.
There is, but it’s at high quality levels. If you’re using WebP for thumbnails or other lower quality situations (Which was the original intended use) then WebP will give you better quality than JPEG for a given filesize.
For lossless uses it’s even better, the format is much more limited than PNG, but in the common cases it beats it.