I realise sensors come in other aspect ratios, but I didn't want to spend the time researching and listing them all. Some sensors are 4:3 (like the IMX363).
But that's irrelevant to my point that the sensor is not square which means you lose more resolution cropping to 16:9 in one orientation (usually portrait) than the other.
Many sensor are 3:2 or non trivial ratios because of how the color filter pattern is aligned. Why do you think the sensors are 4:3?
I realise sensors come in other aspect ratios, but I didn't want to spend the time researching and listing them all. Some sensors are 4:3 (like the IMX363).
But that's irrelevant to my point that the sensor is not square which means you lose more resolution cropping to 16:9 in one orientation (usually portrait) than the other.