Codecs with built-in blurring always totally crush in "Tiny" demos. However, these are only good for demos where viewers care about not seeing artifacts, rather than appreciating the content.

For realistic scenarios, you can't use compression that makes faces look airbrushed, makes wood and hair look like a plastic imitation, etc. If your designers/marketers/photographers care about "grain" in photos, they'll hate you for applying benchmark-winning aggressive smoothing and deringing.

Note that when you switch the benchmark file size to "Medium", the difference is not that big. On "Large" all codecs, except some pathological cases, are nearly identical.

And that makes JPEG stay, despite all newer codecs being "unbelievably" better. Everything newer than JPEG can smooth out blocking artifacts, but quality levels useful for still images don't exhibit blocking in the first place.