I don't get that, Instagram automatically crops photos to 1x1. No need for the camera app to do so for me.
But the camera app does HDR, instagram doesnt. Instagram takes an age to focus and is just pure crap, the camera app is awesome.
Why are they not 16:9? Because it would mean cropping the image and they then wouldnt be 8mp, they would be less.
Your thinking to make it 16:9 you add extra to the sides. But it doesnt work like that. It zooms in and takes it off the top and bottom. Why? Thats just how these things work. It's how it does the video because its a square sensor. not rectangle.
And why do industry standards matter? Because they are standards, cant have people running around making up their own rules all the time. Why do we not have pictures which are boobie shaped? That would be awesome?