- Mac OS, iOS, and Safari support JPEG-XL
- Windows has first party JPEG-XL support as of this year (admittedly it's opt in rather than default)
- Essentially every major image processing app, editor, or drawing app supports JPEG-XL
- Firefox has preliminary support for JPEG-XL gated behind a feature flag and the nightly release.
- The JPEG-XL team is writing a direct port of the reference libjxl library into rust[1]. There already exists a third party rust port by some of the mainline contributors and it has ironed out a lot of the issues with the porting process prior to this mainline port. This first party rust port is intended to be gradually brought up to a hardened, production ready state.
- Mozilla has stated they have no objections to fully adopting JPEG-XL in Firefox once the rust port is production ready [2].
The last major barriers other than getting the rust code production ready will be chrome and android's first party support/adoption.
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TLDR: JPEG-XL is very much not dead and instead people are nose down working hard to continue pushing its adoption forward.
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