A previous dev has prompt which the GTA 6 map needs to be scaled-down and more densely packed. Having said that, as leaks have continued to trickle out of Rockstar, modders have recreated the GTA 6 map in GTA 5's engine which supplies a way of its massive scale. https://gtasixtrailer53186.sharebyblog.com/35208334/grand-theft-auto-6-steam-options