JPEG XL is a modern image format designed to improve upon existing formats like JPEG while offering features such as lossless compression, HDR support, and better performance. DNG (Digital Negative), on the other hand, is primarily a raw image format created by Adobe for digital photography, aiming to provide a standardized way to store raw image data.

While JPEG XL has several advantages, such as better compression and versatility, it is unlikely to make DNG completely obsolete for several reasons:

Different Use Cases: DNG is designed for raw image data, preserving all the information captured by the camera sensor. JPEG XL, while it can handle lossless compression, is not a raw format and may not retain all the same data as DNG.
Editing Flexibility: Photographers often prefer raw formats like DNG for their editing capabilities. Raw files allow for greater adjustments in exposure, white balance, and other settings without degrading image quality. JPEG XL, even in lossless form, does not provide the same level of flexibility.