I find JPEGXL much better at medium and large sizes for the sorts of artifacts that bother me, on most images. For example in this [1] comparison, AV1 is clearly degrained, losing the very fine detail.
Note that achieving high quality results at low bitrates is not really a goal of JPEGXL, or the codecs it's based on. For example the PIK readme contains the following note:
> It prioritizes authenticity, a faithful representation of the original, over aesthetics achievable by by hallucinating details or 'enhancing' (e.g. sharpening/saturating) the input.
So as I noted in the OP, it's not a very fair comparison with bitrates this low, but I think JPEGXL holds its own.
Note that achieving high quality results at low bitrates is not really a goal of JPEGXL, or the codecs it's based on. For example the PIK readme contains the following note:
> It prioritizes authenticity, a faithful representation of the original, over aesthetics achievable by by hallucinating details or 'enhancing' (e.g. sharpening/saturating) the input.
So as I noted in the OP, it's not a very fair comparison with bitrates this low, but I think JPEGXL holds its own.
[1] https://afontenot.github.io/image-formats-comparison/#eaglef...