Glad to see it happen. I'd prefer it there was just one format rather than both jxl and avif, but at least it's the final nail in the coffin of webp which seems to have accomplished little but annoy people for not much gain.
The wider ecosystem support is still far from commonplace, but it is slowly changing. iOS 18 wouldn't work with .jxl in Photos, but 27 does. Similarly, quick look and preview works fine on MacOS 27, thumbnails show up properly etc. I also found no issues with .jxl on linux, and image editors are slowly adding support as well.
Plain old jpg will still be everywhere for the next decade, but I'm glad that we finally have superior options with no real downsides, and without all the patent bullshit to boot.
What issue do people have with webp?