1. Not true before modern AV1 encoder got major improvements in the past 3 years. There is no reason why JPEG-XL can't be improved in the low bpp range. JPEG itself got improvement 20 years after its initial introduction. Not to mention the last time I check, JPEG XL is still better at high end fidelity.
2. JPEG XL lossless can be 10-13% or in some cases up to 50% better. Of course WebP could also be better in some cases. And again, JPEG-XL potential is far fully optimised. Both in encoder and decoder.
On another note, the AOM camp should really have played the AV2 card suggesting it to be better.
I talk about this in the article, but while I agree JXL can get a lot better (prob as good as current libaom) its coding tools are much harder to use – e.g. splines vs dir pred. And I think the sometimes better sometimes worse lossless argument is still not really a super compelling case?
2. JPEG XL lossless can be 10-13% or in some cases up to 50% better. Of course WebP could also be better in some cases. And again, JPEG-XL potential is far fully optimised. Both in encoder and decoder.
On another note, the AOM camp should really have played the AV2 card suggesting it to be better.