It’s smaller than png which a company that shows images really likes because it’s cheaper so to force adoption they convert a bunch of images to .webp on google images
The problem is that 1. It hadn’t been adapted anywhere so people would have to convert it back to png to use 2. It is worse in every aspect to jxl files so Google has had to block the adaptation of jxl on the web as much as they can (jxl retains more quality and is half the size of webp)
Currently only webkit browsers support jxl out of the box. Firefox has had it in their nightly builds for years now but have never moved it into standard