You average Elden Ring side dungeon is multi layered and has more different traps, enemies and platforming than 1 of the dozens of literal empty flat caves, mines and ruins in Dragon's Dogma 2. There's a lot more quality to Elden Ring in general, especially in open world. The DLC also mastered using open world layout as large setpiece. You go from a plateu and descend into cliffs and graves to another fort which has more layers under it. Even if the base game doesn't have this and has some filler dungeons that are small caves and contain essentially few enemies, a boss and rewards, the majority of bosses, most dungeons STILL are actually very large and have unique gimmicks like shaded enemies, chariots, traps, miranda flowers, etc...
Elden Ring open world also works well because all enemies and dungeons feel part of that piece of world there, like bandits ambushing the highway, or wormfaces near Leyndell and Misbegotten roaming near Castle Morne. Dragon's Dogma 2 dropped this from the original because the world is larger and the enemy variety isn't there, which means across that road you'll just find another cyclop randomly wandering there.
Dragon's Dogma 2 open world is still Rage (2011) tier and we are still traversing overglorified canyons.
