Getting back to the OP - good question. IMO, jazz ended in the late 60s and all any "jazz" artist can do is to replay what has already been created. Before anyone kneejerks to say how ridiculous this is, keep in mind that many forms of music have ended. Homophonic music ended, Baroque ended, Classical ended, Romantic ended, Punk ended... Jazz ended. So what? There are still musicians performing classical, romantic, punk, disco, jazz, etc. If you like the music, listen to it. Sounds simple, but it seems to generate a lot of arguments.
The State of Jazz
I was recently listening to "The Best of Diana Krall" LP. It is an amazing album. But later, I reflected on the fact that she sang almost entirely 'standards,' which means the songs are all at least 50 years old. Then, I thought, why hasn't the Jazz Community produced any more recent songs that have become standards. Then I thought: it is most likely, that the same standards (i.e., basin street blues; willow weep for me, etc.) will be sung for the next 50 years--and I wondered, are we producing any songs today that will become standards. I don't think so. Bu, why not?