I'm not sure why you think it's lower res. It looks about equivalent to me. The trees look a bit odd in Google maps, but the quality of the building windows and cars looks about the same.
Here's a more nuanced theory: The building fronts, cars, etc look great because they are from street view. The roofs, treetops, etc, look terrible, because they are from satellite.
The roofs, treetops, etc. look terrible because the depth data is significantly lower resolution than the photos. This causes the deformed polygons you're seeing... The actual resolution of the photos of the roofs/treetops are just as good as everything else, they're just stretched over bad 3d data.
