Because lots of people are hoping Google will change is mind and this is a small concrete step towards that.

Is there a good writeup about why people want this over other, existing formats?

I'm not aware, but the gist is that it's in some circumstances better than AVIF in size and/or quality. Both of the new formats are wayy better than good old JPEG and PNG, but AVIF is the one Google is pushing.

> but AVIF is the one Google ...

but AVIF is the one Google, Apple, Edge, Firefox are pushing...

Let's not be misleading here :)

Sure, everyone else is pushing AVIF too. And I don't mind, it's a great format.

> Is there a good writeup about why people want this over other, existing formats?

All the existing JPEG files can be converted to JPEG XL while gaining 20% size and still having all the exact same data. There are, what, tens or hundreds of billions of JPEG files out there for which the "original" (RAW or anything) is long gone (or never existed) and people don't want a "photocopy of a photocopy".

You can even decompress the JPEG XL back to the original JPEG file, bit for bit.

For that alone there shouldn't be any question: it's a wonderful feature.

In addition to that Apple / Safari are going to support JPEG XL and there are huge number of applications supporting that format.

People don't want this "over" existing formats. They want this in addition to other formats.

And I think they'll get it.

The fact that JXL is a new convenient crusade for people that hate on Chrome. You'll notice that noone is screaming at Mozilla for the same choice.

mozilla didn't remove their jxl support? It's behind a feature flag, like it always has been, but that doesn't mean they will get rid of it or never unflag it.

Exactly, it's not enabled either and there's no plans to. Neither for Edge.

it is implemented, it's just not released. if there's no plans, why did they add the feature flag to begin with?

Same reason Chrome did.

Chrome team themselves quoted no interest of those browsers as the reason for removal of the flagged code. Seems like an obvious way to pressure Google into supporing JXL would be to get Mozilla to launch their support, together with Edge and Safari?

but you do understand the difference between getting mad about a hypothetical situation vs something that actually happened, right?

this has nothing to do with what i am talking about. the issue is legitimate but there are no news or interesting insights here.

I am. It’s worse than Chrome in a way frankly in that JPEGXL is only supported in the Nightlies behind a flag.

However Mozilla has not completely dropped the feature like Google.

Mozilla's JPEG XL feature request is closed in a way that not possible to add comments or express interest.

Chromium's JPEG XL feature request is marked wontfix but still possible to comment or express interest (star the bug).

As a loyal firefox user since the 0.5 release which took 30s to start up, Mozilla is a non-entity these days. It exists solely so that Google can avoid legal disputes. In the mean time, a bunch of grifters have taken over Mozilla for their own financial purposes and push some activist causes rather than a solid browser.