Why is this only a provisional triumph for Priam?

Priam uncovers Hector’s body and weeps, while the carter thinks about how his adventure is nearly over and about his granddaughter. They come home in triumph, but only partial triumph: after all, it is only a momentary victory, and there is little to celebrate about bringing your son’s body home.

"It is only a provisional triumph, of course;...And what sort of triumph is it to be bringing home the body of a son? But he has done something for which he will be remembered for as long as such stories are told. He has stepped into a space that till now was uninhabited and found a way to fill it. Not as he filled his old role as king..."