Point lights have a position in space, and affect objects less with distance. An intensity of 1.5 is similar to “1.5 candles”, and at distances of hundreds of meters you won’t see much. You can increase the intensity, decrease the distance, decrease the decay, or some combination of these. Setting up a simple GUI (with lil-gui, for example) makes it much easier to find the right combination of values.
Directional lights have infinite distance and no decay. They’re often used to simulate strong direct sunlight.