Geometry doesn't determine how a surface looks when lighting bounces off it. That's determined by the multiple layers of texture surface information that can make it look like metal, or plastic, paint etc. Physically base rendering materials.
Normals are then used to add surface detail to create a sense of depth to the texture when appropriate, like rust on metal being slightly extruded, which when combined with proper lighting further enhances the illusion of reality.
Fine details in geometry certainly combine with the lighting to create a far more detailed and real scene, but it's the combination of this, PBR materials and a modern lighting solution which sells the illusion. You seem to be focused only on geometry as the means to achieve these results.
Geometry
None of those small geometric details would actually cast shadows discernible were not for UE5 new VSM scheme and SS-Shadows. Better geo gives lighting better cues, but better lighting makes that better geo actually pop. Neither loooks good enough in isolation.
There is more like shadows. You have light reflections which highly depends on the angel of the surface which the lights is hitting. Or the light which is pasing a ruff edge on acorner will look different like a streight edge.
I did test differnt lighning. I don't see any big different between lumen and screen space her. But what i see are details which the geometry bring on this game.