What should be the size of an open world game?

Question

3D

I'm making an open-world self-development game on junks, but I don't know what size to choose.
And what is the best way to put the terrain and what to add objects to or completely everything in 3dmax

Answer 1

(Number of points of interest)/size=const. The larger this constant, the better. It is better to spawn objects at runtime.