CS1 was by no means a complete game if we consider how many DLCs and core functionalities they added and overhauled on it during the past ten years. On those terms, CS2 is equally a complete game on that regard.
Do bear in mind that the core game of CS1 at launch, and even a year after that, was missing some pretty important and essential features such as day-night cycle, weather, several transit options, terrain modification tool, just to mention few.
I suggest you reminisce on that state with the video City Planner Plays few months ago