TLDR: Pixel level perfection, crisp and sharp photos.
General consumer cameras advertise their cameras by their pixel count. It is easy to understand by customers and easy to market. However, the resolution only tells a small part of the story on how good a camera is.
More megapixels mean bigger enlargements. However, if you zoom into the photo captured by your 16MP smartphone, you will realize that you are just zooming into noise. There is no real information and is a waste of storage.
You will get poorer performance even without zooming in, as the gaps between pixels are not light sensitive and the high megapixel sensors collects less light.