One flight per day with 500+ pax with maybe one or two intermediate stops and a crushed check-in and waiting area at both end terminals
Who operates them at that capacity? QF certainly doesn't, with only about 40 extra pax than a 744. I don't believe EK or SQ operate anywhere near the 500 pax. Not if they're wanting to have all the creature comforts of individual "suites" and extra roomy comfort for their passengers.