You still don't get it. The world of digital images is much, much bigger than just Chrome. Chrome may be the largest player, but Adobe, Windows, iOS, Safari, Edge, Firefox, JPEG, MPEG, Android, Samsung, Nvidia, Facebook, Instagram, YouTube, and so many others play a part.
Chrome doesn't want JXL. That much is clear. But everyone else is looking at it objectively, and the objective truth is that it's a damn good codec. So Adobe is balls deep in it, and that's been enough to get a few other major players on board. At the rate things are going right now, especially if Windows adds support like they've been signalling, Chrome alone cannot stop it. And Chrome will not die on this hill.