If you go by numbers, then it's still not impressive.
360kgs of fuel per pax on the fatboy, versus 308kgs per pax on the T7.
And apart from that 6 tons of remaining load for freight on the fatboy versus 12 on the T7.
The fatboy was planned to do the westcoast, it still can't reach it. It has been planned to uplift masses from the subcontinent, down there they are intentionally slow to build up the compatible infrastructure. At the moment it is doomed to fly routes that make it look very thirsty.
How the beancounters show more profit on the 380 remains a mystery to me. Especially when considering how many customers have paied Y and have been upgraded with miles or simply because of overbooking in the back.