> Does WebP provide a savings against jpeg for these photos?
“WebP seems to have about 10% better compression compared to libjpeg in most cases, except with 1500px images where the compression is about equal.”[1]
mozjpeg JPEGs + AVIF in a <picture> element is the way to go now. You will probably always want to serve JPEGs as an alternative WebP and AVIF and that makes WebP is a waste of disk space for lossy compression of photographs.
I'm amazed the “WebP is such a goated format” blog post made in to the front page of HN.