[Slightly off-topic]
Assuming the last column is the cancellation rate (%), what sticks out is the contrast between Rex and Virgin.
Rex typically schedule longer turn arounds in Melbourne and Sydney for their 737 fleet compared to Virgin (and JQ/QF for that matter). They also have a lot more slack in their jet schedule, so they can mitigate cancellations more easily. Also, when Airservices issue the daily ATFM plan and flow rates are reduced, Qantas and Virgin are always going to be impacted more by virtue of the volume of flights they operate compared to Rex. The crewing issues at Virgin would also have influenced those figures.
Sort of on topic, sort of not … Rex often boast about having the best OTP of all the carriers, but the data doesn’t break down the performance of the 737 and Saab operations. In December, the Saab fleet did some heavy lifting to put Rex on top.
Because the monthly data breaks down performance of each route, it’s easy to calculate OTP for the 737 fleet. Using the most recent data, Rex had (roughly) a 61.0% on time arrivals rate, and 62.9% on time departures rate for their 737 operation in December. One caveat: that doesn’t include ADL-BNE/BNE-ADL because Rex wasn’t included in those individual route break downs. Compare that to Qantas mainline with 67.8% for arrivals and 70.2% for departures in December.
For cancellations, Rex clearly has the lowest rate, but their claims of having the best OTP is classic Rex spin. Rex like to compare their domestic jet product with Qantas mainline, so if we apply that comparison to OTP, using the most recent data Rex did not have the best OTP for mainline operations.
I have gone slightly off topic, but to relate back to the topic (and to answer your question about VA vs ZL
@tdimdad), I think the OP has genuinely been unlucky. Their frustrations are very valid (I’d be frustrated too), but if we look closely at the data, the QF cancellation rate has held steady over 2023 and there isn't anything to suggest an uptick in cancellations. We'll have to wait for the January 2024 data to see if anything has changed.