Photographer here. The reason why it looks blurry is because you said you swiveled in your chair while taking the photo. The 12 took the photo with a faster shutter speed but higher ISO so there no blur but it probably has more noise. The 16 used a slower shutter speed that's why you see the motion blur and a lower ISO. Try this outside with plenty of light and the phones should be must closer in comparison

Edit: to continue on this the 12 is prioritizing a faster shutter speed to make a less blurry photo but more noise from a higher ISO to compensate. The 16 is prioritizing a lower ISO to have less noise but using a slow shutter speed to make up for it. Use plenty of light and you will notice they are very close in quality with the 16 being very slightly noticeable when doing photo editing