Which comes back to the original question in Post #1:
Should SYD reduce their capacity until the ATC issue is resolved
I suspect Airlines will not unilaterally reduce their flights based on their perception of the safety issue at play. I suspect they will only do it if everyone has to do the same.
The problem could also be easily solved (on paper) by reducing the Sydney Curfew from 2300-0600 to 0000-0530 for the next year and then review.
An extra available 1.5 hours mean the max daily cap of 1360 flights translates to 73.5 per hour instead of current max 80/hour
This is approx 9% which would go some way to alleviating the overall 10% shortage and might even reduce the unexpected sick leave on some days.
This would allow the same flights /day but spread out over longer period
........,,
And will also relieve the non existent
looming jet fuel shortage