It's a philosophical difference I suspect. To quote from your site:
"I believe Web codecs should be purpose-built, efficient, and narrowly scoped to the needs of the Web.... [JPEG XL] is meant to be everything to everyone... Not to mention an additional compatibility headache now exists for anyone just trying to download an image from the Internet and use it somewhere"
Browsers aren't trying to be narrowly scoped anymore, nor made just for the web (Rust and LLMs must have improved their confidence regarding security). Other usecases (like PDFs and cameras) clearly benefit from JPEG XL. Once support was added, it was easy to just turn on for the web. After all, they need to consider the opposite case where someone creates a jxl image and tries to upload it to the Internet. They might even think that having a format that is everything to everyone is useful and eventually the (en)decorders will improve.
"I believe Web codecs should be purpose-built, efficient, and narrowly scoped to the needs of the Web.... [JPEG XL] is meant to be everything to everyone... Not to mention an additional compatibility headache now exists for anyone just trying to download an image from the Internet and use it somewhere"
Browsers aren't trying to be narrowly scoped anymore, nor made just for the web (Rust and LLMs must have improved their confidence regarding security). Other usecases (like PDFs and cameras) clearly benefit from JPEG XL. Once support was added, it was easy to just turn on for the web. After all, they need to consider the opposite case where someone creates a jxl image and tries to upload it to the Internet. They might even think that having a format that is everything to everyone is useful and eventually the (en)decorders will improve.