Well the new city coming in SB will be entirely seamless and even have open rooftops. That is a step in the right direction.

Also while having a massive city is great for a sense of the world, Do you want to spend god knows how many minutes walking from place to place just trying to get simple stuff done? It will add up to hours of time wasted just for the sake of a big city. I am personally fine with a cut down city. Just use the horizon to display how big the city is, no need to be able to go everywhere.