Since 2019 Cathay has disposed of 12 B777-300ER's and added 11 A350s with another to come before the year end, all while not reinstating service to second tier European cities (Dublin, Gatwick, Brussels, Barcelona and Rome) which were served by A350s so it is not surprising that the A350s are taking over flights previously served by B777-300ERs. A little more surprising is the number of Aussie flights using B777-300s in place of A350s but I suppose this is due to a combination of cargo demand/capacity and the demand on limited numbers of qualified flight deck crew.