There are already some huge maps out there, Just Cause 2 and 3 both have maps at around 1000km2, and those games are beloved by their players. But if the next Cyberpunk game was announced with Night City now being the size of an actual large metropolis, say like New York, would you say that’s too big? What determines what “too big” is?
Ease of travel and speed of travel. Even a small map can feel cumbersome, repetitive, and boring. If the missions are designed poorly, and the game mechanics ignore an entertaining user experience, walking down the same hallway a thousand times can feel like a chore.
“Too big” is a relative feeling that involves many factors.