I can't belive it's a technical choice, because it's not like just hidden corners have low textures. The prioritisation makes no sense if it's intended. You can walk up to dozens of unusable random doors in the slums, for example, and they look fine, and yet a door you actively use frequently resulting in close up camera shots, looks like a PS1 texture. At all times. I don't think it's a huge issue because the game looks stunning most of the time, but it's jarring because of how noticable and central it is when it does rear its head.
