For years now the only way that Jetstar can compete with Qantas on many routes has been when Qantas abandons those routes.
Correct.
Note the performance of the brand where they have to stand on their own feet.
JQ Asia - fail
JQ NZ - fail
JQ Japan - fail
JQ Vietnam - fail
JQ Int - shrinking massively, + ex QF routes (mel - sin, syd - hnl, cns - nrt, cns kix) still a fail
JQ HKG - stop it hurts