Absolutely. Simply unscrewing the Huffman stage from the bottom of JPEG and replacing it with a more effective, modern lossless stage kills webp's gains and doe

Absolutely. Simply unscrewing the Huffman stage from the bottom of JPEG and replacing it with a more effective, modern lossless stage kills webp's gains and does not incur in generation loss - the image is pixel accurate to the source jpeg. You'll probably know this already, but Brunsli made it into the JPEG XL standard. I'm quite happy about it!