The same 8 Mpx but always the best picture quality. How ?

Question

Since iPhone 5 there are the same number of megapixels but iPhone always have better camera and the best picture quality  comparing to other flagships with 13,16,20 Mpx. How they make improvements without raising the number of megapixels ?

Answer 1

It`s Apple`s little trick to improve the camera model, for example in the 6 model, the aperture was improved to 2.2 and the lenses were covered with a delicate sapphire layer to increase it lifetime