Actually JPEG XL is based in part on Google's PIK format. The Zurich team from Google Research (which developed PIK and Brotli) is even actively working on JPEG XL to this day.
The reason why Chrome (also a Google product) removed it at first is more likely to be internal politics. Google is a very large corporation after all, with each faction within it having its own priorities and alignments. In the case of Chrome the team there are probably more aligned with the AVIF/AOM team than with Zurich/PIK when it came to the next-gen image format to be pushed (which would explain why Chrome did not have problems with Brotli, because there wasn't a competing Google faction that is developing a replacement for gzip).
The reason why Chrome (also a Google product) removed it at first is more likely to be internal politics. Google is a very large corporation after all, with each faction within it having its own priorities and alignments. In the case of Chrome the team there are probably more aligned with the AVIF/AOM team than with Zurich/PIK when it came to the next-gen image format to be pushed (which would explain why Chrome did not have problems with Brotli, because there wasn't a competing Google faction that is developing a replacement for gzip).