Similarly why CZ never files widebodies between CAN-SIN pre-pandemic, even though they fly 5 times a day across this high-competition route. It has to do with the timing of the flights, by switching any of its existing flights to widebody, it has to reduce its frequency inorder to stay above the turning point(Almost all of the CAN-SIN are always 60-80% full even with A320s/737s), and by reducing the frequency, CZ will no longer posses the upper hand against the Star Alliance and its partners(TR,SQ,ZH) in the route.