Context: Even though Chromium has native support for AVIF, a very nice image format, Microsoft goes out of their way to remove it from Edge, which is a chromium fork. Jpeg XL (JXL) (not to be confused with Jpeg (JPG) or Jpeg 2000 (jpg2k) ) is another nice image format, which, IIRC, is only supported in Firefox.
Safari is the only browser that supports Jpeg XL. Firefox does support it if you enable a flag but IIRC from bugzilla their implementation is currently not great.
If a browser feature needs to be enabled with a flag it’s not really supported since an extremely tiny portion of users will be able to use it, and it’s often buggy.
https://caniuse.com/jpegxl