I choose to believe that Sophia was the goddess of gravity, whether or not we knew it. Thus, having beaten her, gravity is too scared of us to hurt us any longer.

More seriously, no, there’s no lore reason. It was just really annoying to take fall damage in dungeons and raids and have to heal up afterwards, and it served no purpose beyond and enforced wait at the bottom of a fall. So now fall damage only happens in the general world instead of instances.

That said, you can absolutely still die from a fall… if you’re in combat. The “lose all but 1 HP” safety is not there if you’re actively in combat when you hit.

During treasure maps with the FC, one of the folks in the party backflipped off the edge of a cliff in Lakeland right before the final mob died… and he went splat. The cliff in question is now known as “the <name> Memorial Drop” among our FC, in his honor. (I omit the actual name to protect the guilty.)