Encoding AVIF is very slow for large images.

Instead of using a breakpoint style approach with several predefined sizes some site generate images related to viewport size at very fine granularity and even changing the viewport by 1px will cause the AVIF to be regenerated

In these cases you can notice services like Cloudinary take several seconds to generate the new variant if it’s a large image

if I understood well, AVIF encoder is quite fast for ugly qualities and very slow for standard and higher quality. https://cloudinary.com/blog/contemplating-codec-comparisons#...