webp was around since 2010 and has google's backing. Microsoft tried their own thing (Jpeg XR; 2009) and the actual JPEG committee announced their work Jpeg XL (with google backing) a while ago, while Apple switched to HEIC/HEIF as of 2017 (HEIC is like webp just based on HEVC aka H.265 instead of vp8 i-frames; and it's a patent mess of course).
There is simply no reason why people in 2016 or now would be interested in a format from 2000 that was a patent minefield until at least 2016.
Except for JPEG the alternatives are also patent minefields...
Are people just more cavalier about the patent risk these days? The problem with JPEG2000 wasn't the patents we knew about, it was the possibility of submarine patents. People were still wary after the GIF debacle. Nobody wanted to be charged $0.05/image after the fact when they've delivered literally billions of images. Plus the courts were seen as very favorable towards patent holders, even when they were acting in bad faith.
There is simply no reason why people in 2016 or now would be interested in a format from 2000 that was a patent minefield until at least 2016.