A good read on Qantas Vs Virgin use of A330 & Boeing 737
Interestingly, both airline seem to be adopting the same kind of strategy of using smaller aircraft to improve customer's experience.
Virgin look like diverting the A330 to Asia route.....
https://www.ausbt.com.au/qantas-vs-virgin-australia-airbus-a330s-on-east-west-flights
Cheers