For interest, I did a search on ITA Matrix for forward journey SYD-JFK on Wednesday 7 February 2024, returning ex JFK exactly three weeks later on 28 Feb.
In J, cheapest was OZ at an amazing A$6476 return, then PR $7049, JL $7211, NH $7255 and SQ $9137 return. I've omitted AI and AY
AA was $13,737, DL $15,356, and (wait for it) QF $19,185. Only UA at $22,951 was more expensive.
NZ didn't feature as I restricted the search to a Wednesday: NZ flies SYD or other Australian airports-AKL-JFK on different days of the week.
Some of the less expensive carriers are competitive time wise (JL probably the standout in that regard) and others suitable for leisure travellers (PR for instance) with a pleasant stopover at the intermediate airport to break up the monotony of the journey.
Why would anyone paying for their own ticket choose QFi at almost three times the price of better, or very acceptable carriers? QFi is renowned for having poor service. It only offers a minimal time saving, yet charges far more than most.
More and more, one obtains the impression that a very sizeable percentage of QFi travellers in J have their tickets paid for by someone else (such as accumulating FF points through a company or a government agency/department) and sadly don't know the joys of using competitors where service, meals and onboard amenities are first class and the staff never, or extremely rarely, grump at passengers.
No wonder Mattg didn't feature a typical (eye watering) fare estimate!