Personally, even if Chrome goes ahead with removing support I hope JPEG XL will "win" in the long run by being an attractive "universal" format for all other use-cases for image compression. So in other words: that it finds an ecosystem elsewhere, slowly takes over outside of the browsers, and then the browsers will adopt it after all.
For example, I remember reading somewhere that there are people looking at whether or not it makes sense to convert all of the existing JPEGs to JPEG XL on their servers for storage, then reconstruct the JPEG when needed. If so, then there is a niche where it can find adoption even if browsers don't support it yet. It also looks like it might find a use for medical and scientific imaging.
What I personally really would like to know is if it would be possible to losslessly recompress the RAW files from my camera. It looks like it should support everything required, and the claim that it "is the first serious candidate to become a universal image format that “works across the workflow”, in the sense that it is suitable for the lifecycle of a digital image, from capture and authoring to interchange, archival, and delivery" kind of implies that it is, but I haven't seen anyone say it out loud yet.
Because I must say: DNG is really slow and clunky to work with, and I bet has terrible compression on top of that.