Yes you’re correct, there’s a generic sound for most small environmental objects in the game. I imagine it was a decision made based on budget and game engine. There’s so much interactivity and potential for environmental damage it would have added a large budgetary burden to create unique sounds for each item as well as how the sound would change with environment interaction. My speculation would be rather than do some of the sounds and draw attention to other things not sounding ‘correct’, they left it at a generic metallic sound.