I looked through quite a few of these test images and it seems that AFIV is better overall than JPEG XL.
Sometimes it's really clear. E.g. for the "US Open" Image, AVIF "tiny" (23.6 KB) looks as good as JPEG XL "medium" (46.3 KB), despite the substantial difference in bit rate:
In some other cases it's less clear, and sometimes AVIF denoises too aggressively, e.g. in animal fur. JPEG XL has more problems with color bleed. Overall it seems to me AVIF is significantly better, especially on lower bit rates.
Sometimes it's really clear. E.g. for the "US Open" Image, AVIF "tiny" (23.6 KB) looks as good as JPEG XL "medium" (46.3 KB), despite the substantial difference in bit rate:
https://afontenot.github.io/image-formats-comparison/#us-ope...
In some other cases it's less clear, and sometimes AVIF denoises too aggressively, e.g. in animal fur. JPEG XL has more problems with color bleed. Overall it seems to me AVIF is significantly better, especially on lower bit rates.