Since no other aircraft can fly that sort of time and distance with a comparable payload that efficiently, it is not a show stopper.
Many 777s fly around with next to nothing in their cargo holds when flying a ULH, and it is costing fuel to have that sitting there empty.
Most airlines do not have city pairs they want to serve that far apart, that is the limiting factor. Probably only a dozen airlines in the world that would have the need for it.
Between ULH routes those 777’s can use those cargo holds profitably on shorter flights
As many airlines do, it gives the operator the
flexibility to use an expensive asset productively in the manner they choose and not have it sitting around for hours between ULH sectors