As someone who has designed a customised camera with a CMOS sensor, I feel the urge to disagree: in my experience, the biggest issue for quality was that the se

As someone who has designed a customised camera with a CMOS sensor, I feel the urge to disagree: in my experience, the biggest issue for quality was that the sensor readout generates heat and that heat triggers random charges in the sensor. Using a sensor with larger pixels means the readout energy is spread over a larger area, thereby having a lower intensity. So in a way, a larger sensor works like a larger heatsink. This effect is also why astronomy photographers cool their equipment. You're of course correct that the better lens helps. But a bigger sensor can also be better by itself.