You can manufacture two computers at the same time, with every component physically perfect with each other and start them at the same moment and they STILL will run differently after only a short time.
Air is different in two parts of the room. Ambient radiation is slightly different. Bit errors start right from the beginning and accululate and are garbaged differently,
Two identical twins could eat and poop at the same time identical foods but they’ll still receive slightly different nutrition.