If it's backwards-compatible with standard JPEG decompressors, then you've just made a better JPEG encoder. And that's great, and people are still doing that al

If it's backwards-compatible with standard JPEG decompressors, then you've just made a better JPEG encoder. And that's great, and people are still doing that all the time, but we don't need a whole new ISO spec to do it. All of the JPEG-XL enhancements are new additions to the format that aren't backwards-compatible.