A previous dev has suggested that the GTA 6 map need to be smaller and much more densely packed. Even so, as leaks have ongoing to trickle outside of Rockstar, modders have recreated the GTA 6 map in GTA five's engine which provides a sense of its enormous scale. https://israelgcwtr.blogdigy.com/5-essential-elements-for-grand-theft-auto-6-ps5-53459803