I think the case for JPEG XL is not that it's the best at everything, but that it is both quite good overall while also supporting basically every obscure image format feature under the sun. It's the potential USB of image formats.

> while also supporting basically every obscure image format feature under the sun

Except for gain maps :)

I don't really mind because I don't use them anyway. I prefer to use the client's tonemapper. But they are a useful feature that's not supported by (chrome's implementation of) jxl