Additionally, these new apartment complexes are often build in "new areas" of the bigger cities, to grow the city. China is trying hard to reach a level of urbanization comparable to the west, so they need to "grow their cities" somewhat aggressively.
I have lived in two of those newly build complexes myself. First there is not much around, roads, maybe a supermarket and a few stores. The local gov't or the developer offer the shop owners rent-free for a year or two to get them to set up their stores in the new area, because there are almost no people yet. But two or three years later, the apartments are mostly filled (either rented or sold) and the shops are paying rent too, new supermarket have arrived, and suddenly the area has become part of the city center.
Same goes for big roads. In the southern part of the town I live in, there is a huge road grid (6 lane roads, etc) already build, but there is only grassland. Come back in five to ten years, and it will be inner city area. Smart to finish the roads before it is crowded.