>>536606218
D1 has the same or only marignally fewer POIs than D3 but no outposts and secondary objectives to get in the way, and smaller maps to for less travel time between POIs

I full cleared D1 maps and counted the POI spawns and then full cleared D3 maps and counted the POI's,
the larger size of D3 maps makes the 2 or 3 extra POIs not worth the extra time it takes traversing and navigating the map, especially when the D1 maps have the POIs in arranged in a ring while on D3 you do a lot of zig-zagging