Not true. There was significantly less people and traffic in last gen versions of the game. It wasn't simply a visual upgrade, it affected the game play a lot. Riding highways in rush hour traffic on PS4 was a completely different gameplay experience compared to last gen consoles. Rush hour practically didn't exist on last gen. The additional CPU performance of current gen consoles made it possible to recreate a city that felt alive. Last gen port was way too empty. A big trade-off for a game like this.Sure, but GTA 5 also ran on PS3/X360 with identical gameplay. The Switch compares much more favorably to those consoles. The graphics are the only things that changed between last gen and current gen.
PS4 traffic density: