I agree that the choice for JPEG XL is mostly politically motivated: it isn't Google. And its name is derived from JPEG, which is an IETF standard which gives it more clout.
>it isn't Google.
It is Google. The JPEG XL standard evolved from a codec Google made, Google was involved in the standardization process, and Google heavily contributed to the reference implementation of JPEG XL.
https://ds.jpeg.org/whitepapers/jpeg-xl-whitepaper.pdf
Editors:
Jyrki Alakuijala – Google, Switzerland
Jon Sneyers – Cloudinary, Belgium
Luca Versari – Google, Switzerland
Jan Wassenberg – Google, Switzerland
JPEG isn’t from IETF.