They feel strange as there are visible "other pars" of the cities but there is no way to get to them, they exist but can't be reached. Example: New York is the one which this is more perceptible. The other boroughs seen from afar as 3d looking wallpapers, buildings like the Empire Estate in Manhattan and the ones from Brooklyn, along with the Brooklyn bridge itself. They "exist" to give the player a fake sensation of the world being larger and vast than it looks. They are there, but Dominic and the main characters simply don't go there, they don't take a drive to Little Italy or Hell's Kitchen. The NYC map feels weird as we have a lack of bridges accessible to any other part of New York as a nice, decent excuse (we have a viaduct though but it doesn't take us anywhere even with NPC cars being seen driving within it and dispawning) But oh boy, how cool would haven been if they actually designed and included the other New York Boroughs such as Brooklyn, Manhattan and much more so we can drive around and take over rackets from different families. It also doesn't make sense as after Dominic mops the floor with Carmine's family ONLY in that small part of Queens, he says that NYC is his. I think the lore is that Carmine Rosato's goons most likely tried taking over that part that is featured in the game instead of the other boroughs and neighborhoods. Again, would have been cool to chase Carmine's family throughout Manhattan and Brooklyn.