A previous dev has suggested that the GTA 6 map need to be lesser and much more densely packed. Even so, as leaks have ongoing to trickle outside of Rockstar, modders have recreated the GTA six map in GTA five's motor which provides a sense of its huge scale. https://devinzyywt.digiblogbox.com/59943170/the-5-second-trick-for-grand-theft-auto-6-trailer-2