True, but low light on a phone (even an iPhone) is quite different from low light on a DSLR. Noise kicks in very soon on iPhone's RAW files even with relatively abundant light, although it isn't always obvious on Camera app photos due to the strong noise reduction algorithm applied to all photos.
I doubt we're nowhere near the point where more pixels is a better compromise than bigger pixels.
May be. What we saw with iPhone 12 vs 12 pro max comparison in good light is that the larger pixels brought nothing in this situation. May be it is because of Apple image processing. On the other hand, increasing the pixel count without decreasing the pixel size always improve both detail in daylight and low light performance.
Keeping the iPhone 12 1.4um pixel size, the 1/2” sensor from the 12pro max would have had around 18Mpixels, with, obviously, better low light performance and better daylight details than the iPhone 12 sensor. Thus, because the 12PM does not show more details in daylight than the 12, more, smaller pixels on the 12PM would have increase the amount of detail and the cropability. 16Mp at 1.5um also fit...
May be the reason why Apple is not increasing pixel count has nothing to do with low light. May be it is due to image pipeline limitation. Their processing is based on a lot of frame, and limiting the sensor to 12Mp limit the amount of data in the pipeline.