The first question is: Why risk perma-death? Because Blizzard wants you to, and the developer is prepared to reward you handsomely for the risk you undertake. Even the Dark Souls games don’t punish you too hard for dying – not really. Sure, you may lose Souls and have to retrace your footsteps without perishing again in order to reclaim your valuable prize, but beyond that, the eternal ‘live, die, repeat’ loop loses some of its bite.
Permadeath, in Diablo, has serious stakes. Anyone that braves Diablo 4 on its imposing, intimidating, incredibly challenging difficulty sets out to do so in the knowledge that, at some point in their doomed character’s career, they will find themselves staring certain death in the eye. And the loss of all progress, gear, and experience along with it.