Note that Google Maps can be described as "a hodge-podge of different maps"; a satellite map and a street map (and sometimes a 3D map if you use Google Earth), and using that hodge-podge is indeed more convenient than using one representation that tries to combine them all.

I know that you didn't mean hodge-podge in the same sense (you were talking of 3D-> 2D), but I think that Google Maps is a good illustration of how having different views of the same reality is useful.