Remove 10% of the seats, they are heavy and cumbersome, that will reduce weight in the cabin and allow more space to move around. It will also reduce the APS weight of the aircraft, it will also reduce the amount of food and drink that needs to be carried as there are fewer people on board to consume it, which will reduce the weight, further meaning less fuel required, and less trip fuel requires less tanking of fuel to carry that fuel, so further economies will be made. The cabin crew will have an easier time so will be happier in their work, seems like a good idea to me?