What this [removal of support for JPEG-XL in Chromium] really translates to is, “We’ve created WebP, a competing standard, and want to kill anything that might genuinely compete with it”. This would also partly explain why they adopted AVIF but not JPEG XL. AVIF wasn’t superior in every way and, as such, didn’t threaten to dethrone WebP.
[0] https://vale.rocks/posts/jpeg-xl-and-googles-war-against-it