dead for the web. I still store various images in JPEG-XL, have support for it in my image-viewer of choice, can use it in Python's pillow (with a decoder plugin) and lots of other things I use to modify images.

I still have to occasionally convert some images back to jpeg, but the savings from storing all of them in jpeg-xl instead is worth it to me (and avif support is spotty in the same areas, it is only really ahead in browsers and photoshop)

X-JPEG-XL, bereft of pixels.