I think it's a great opportunity for Firefox to stand out by supporting JPEG XL before any other browser.
Imagine images served by Cloudflare and Cloudinary load faster and look better only with Firefox. Firefox was a pioneer of web technologies and it should win the title back, if Firefox just keep following Chrome without any differentiation, why would people choose Firefox?
If the decoder memory safety is a concern, maybe Mozilla can start a crowd funding campaign to sponsor a Rust decoder, even the campaign itself will attract reports and attentions for Firefox.
Mozilla argued AVIF was already supported as a same generation but clearly JPEG XL has many advantages:
Supports from Facebook, Adobe (they're adding export support), Intel and VESA, Krita, The Guardian, libvips, Cloudinary, Shopify
Being a software developer myself, I understand that supporting a new format is not taken lightly. There is the overhead cost for maintenance as you need to pull in security updates and bug fixes within libjxl. There's also the question if yet another format will obsolute this one in the near future.
However, I think JPEG XL is one of those "once in a decade" formats or longer. I can honestly not see JPEG XL being made obsolete in the foreseeable future as it is so advanced and encompassing both lossless and lossy compression alike at very high ratios, as well as animation.
Many focus on the compression ratio alone, but JPEG XL makes several important advances beyond those of competing formats such as JPEG, PNG, AVIF to make it a great "catch-all" format that many of us have been missing on the modern web.
That Google has chosen to currently not support JPEG XL shouldn't impact an independent evaluation by Mozilla, as an independent browser with indedendent goals.
JPEG XL, being an open, highly flexible format with performance to match the decade ahead should logically warrant much greater efforts than what have been seen from the community so far. It is such an important format, that even despite lacking web browser support, we see it becoming adopted in the industry, such as by Adobe Camera Raw, Darkroom, Affinity Photo, GIMP, Krita, as well as KDE and GNOME photo viewers, and within Windows Explorer and more as a WIC extension. This eager adoption is indicative of how much this image format is as a stepping stone from inferior or less flexible formats such as JPEG, PNG, WebP and AVIF.
Interestingly enough, it seems there was initial support implementation in Nightly, however it never made it into beta or release and basically in stale condition (as for now). And, as a person above mentioned, it slowly makes it was into other software, so taking the initiative to be the first popular browser to support it might be game-changing for the whole Web!
The neutral stance is a disservice to JXL as a format. The community has been ablaze with enthusiasm for JXL since this request was introduced & that isn't going to change any time soon. Every piece covering JXL that mentions major browser vendors dropping support has gotten incredible amounts of attention.
Firefox can either support JPEG-XL today, or wait for JXL to take off outside browsers (which it will, and it already is) and have their hand forced. I'd rather be ahead of that curve, personally.
throwing my 2 cents in. love the idea of firefox support. keep supporting open standards first and let the web run with it. would love to see some sites with a "works best in firefox" banner as Mozilla leads the way
I would also like to see JXL support in Firefox, regardless of Chrome's choice.
JXL is the future of image storage, no doubt about that. There is no other format that comes close to the featureset. There are alternatives that are somewhat comparable for web-applications, but not for local usage.
That being said, dropping JXL from the browsers would just lead to the need to convert the locally saved JXL to a browser-supported format for web usage. Sounds pretty dumb to me.
If you want to reduce development effort, drop a less useful format like avif first i'd say...