Megapixels definitely don't matter, except when zooming is needed. This is not a problem for real cameras with optical zoom, but digital zoom is usually crap.
This is the only reason for Lumia's high megapixel sensors, with 40 MPix there is enough pixels to zoom in, i.e. crop the image without loosing details.
I also love the wonderful 25mm wide angle lens Lumia 1020 has. In landscape photography there is always the same issue trying to fit lots of scenery into one photo, where a wide angle lens is needed.
Now there are lots of other phones with really bright optics and good quality sensors, that are in pair, or even better, than 1020, but then their (35mm equivalent) focal length is something close to 28mm, or even more. 100% dealbreaker for me.
Once you get used to Nokia's ~25mm wide angle lens it is impossible to move back to so heavily cropped view angle we see in iPhones and Samsungs.