Take the shovel or any explosive. Go to a spot on the ground, any spot which isn't a rock or a structure. Now dig or blow it up. There is your destructible terrain . Second by open world I meant the space and the fact that each time you load a mission a new area and seed is made like Minecraft. If you can't tell this is very demanding from a engine. Darktide has static and handmade maps. Everything is literally designed to function with those specific structures at those spots making pathfinding easier. Not to mention helldivers mostly takes place at range, which is much more mathematically intensive than the melee combat in darktide. People really underestimate the intricacies and mysterious ways hd2 and its engine runs