So Google contributed to it, but ultimately didn’t invent it and doesn’t own it. In other words, what I said.

As opposed to WebP, which not only do they own, they also own several patents for that cover the entire bitstream. They offer a patent license that is conditional on not suing them. So they basically own and control WebP entirely. They do not own, nor do they control, JPEG-XL. Google owns patents that cover a portion of JPEG-XL, but don’t have full control.