It’s to do with the light and dark. The enemy’s we fight typically go to where darkness manifests. It blots out the light. Without light (our power from the traveler) ghosts cannot resurrect us. That’s guardian’s shtick on why we are resurrected in most places but not everywhere. We aren’t immortal we can die, just look at how in a previous season the drifter when he was lost was being resurrected by his ghost over and over after dying of starvation. It’s just not common knowledge in the game anymore.