The solar farm produces more energy per dollar spent. Rooftop solar is expensive. It produces comparatively fewer kw to amortize the fixed costs over - permitting, getting up on the roof etc.

If a country has abundant land and expensive labor, the money is probably best spent improving grid transmission capacity and otherwise getting the f- out of the way of utility-scale renewables. Places like Pakistan, which is going through a rooftop solar boom, are arguably the opposite - scarce land in the cities, but cheap labor to get up on roofs.

Happy to hear any analyses to the contrary and update my knowledge accordingly.