"The JPEG XL Image Coding System (ISO/IEC 18181) has a richer feature set than existing codecs and can deliver images with similar quality at a third of the size of widely used alternatives."

Its lossy part is being developed by Google PIK team ( https://github.com/google/pik ) + Jon Sneyers (author of FLIF) – some details: https://encode.ru/threads/3108-Google-s-compression-proje%D1... https://encode.ru/threads/2793-PIK-image-format

Lossless conversion from JPEG to JPEG XL and back is a killer feature!