Density rather than size as a comparison axis. Different game, different density profile.
Cyberpunk 2077
Vertically dense, narrowly footprinted. Night City is small but tall. Different design philosophy from GTA.
RDR2
Spatially extensive, environmentally dense. Wildlife and weather rather than buildings. Different density type from urban GTA.
Watch Dogs
Mid-density urban. Less interactivity than GTA, more tech-coded gameplay layer.
GTA 6's place
Trailer evidence suggests very high urban density - probably the densest single open-world city to ship in 2025-2026. Compared to RDR2, less spatial; compared to Cyberpunk, less vertical; compared to Watch Dogs, more interactive.