The boxes go about differently, with a purple box (gold strong box) often holding an item for winning, and silver and bronze for each 1/3 objective in the battleground. It’s intended that the pvp gear are to be less useful in pve, with pve gear being scaled in pvp (pvp gear themselves get a boost)

You can also win conquest points for winning, though ranked would be a faster way to achieve those.

for honor honor primal combat