If JPEG-XL decompressed faster, I'd use it more. For now, I'm sticking with WEBP for lossless, and AVIF for lossy. AVIF's CDEF filter (directional deringing) works wonders, and it's too bad that JPEG-XL lacks such a filter.

JPEG-XL's lossy modular mode is a very unique feature which needs a lot more exposure than it has. It is well-suited to non-photographic drawings or images that aren't continuous, and have never touched any JPEG-like codecs. It has different kinds of artifacts than what you typically see in a DCT image codec. Rather than ringing, you get slight pixellation.