Yes it's a shame.

Jon Sneyers (main JPEG XL designer) :

"According to my benchmarks, JPEG XL also outperforms AVIF at quality settings very much suitable for the web, especially if you compare them at same-cpu-effort encoder settings. If you have data that says something else, could you please share it?"

https://twitter.com/jonsneyers/status/1666062661585367042

https://caniuse.com/avif - 87% penetration. JpegXL have about zero (actually 5% - safari). So, in practice, you can't use it

But it has a great advantage: it is not made by Google (which also is probably the reason why it is not adopted too widely).

I am trying to minimize using things originating from Google.

A bad news for you; it was made by Google, partly (Google Zurich and Cloudinary). It wasn't adopted probably because it didn't originate from the Google Chrome team.

JPEG XL still has too poor browser support to be taken seriously although I hope Safari's move in the most recent version will apply more pressure on Google.

I really hope JPEG XL wins the next generation lossy image codec war, for the killer feature of being able to losslessly convert my back catalog of JPEG photos to JPEG XL photos.