There is also a thing called MTF of a lens, which measures its sharpness and resolving powers. If the absolute very best lenses available for the m43 camera system has a sharpness of 13 perceptual Megapixels, you can bet your bottom dollar that the scrap of glass in front of a smartphone camera is not going to have sharpness anywhere near being capable of resolving 13 megapixels. Its all marketing and also a convenient way of selling more storage space both in-phone and in-cloud.