From what I can tell, the author is focusing a bit too much on numbers, but is unsure why these alternatives haven't gained widespread adoption.<p>The comparison photo isn't great. Even my pedestrian eyes are able to tell that the Webp and Avi conversions result in poorer photos (most glaring example is the tree in the background), so immediately I'd not want my photos created, converted, or displayed in that format.<p>But numbers aside, the main reason is because JPG is 'good enough'. It's the same reason that old protocols like FTP and SMTP still hang around, why customers still want CSVs/Excels over Parquets. If a thing is good enough, it will hang around for a very long time because there's no compelling reason to move away from it. Considering the bloat that websites already present to the user, and the general lack of attention to bandwidth savings in the development stage, AND the existence of 'workarounds' like CDNs, even the development teams have little incentive to look for savings here (for now).<p>There will be hundreds of workflows built around JPG's capabilities as well, right from how cameras take the photos, embed metadata into it, how tools read that metadata. Think of embedded devices and webcams that produce images, which will be running 'in the field' for decades.<p>Additionally it's not just about browser support, which is a very limited way of considering it. For people working with those image types, they will want to know if it's compatible on all desktop OSes, and through tooling like GIMP, Photoshop, Affinity, exiftool, ffmpeg, imagemagick, etc.<p>It'll probably be a good number of years before there is widespread adoption that enable those workflows, at which point we (hopefully) no longer have to care whether it's a .webp or .jpg.