I think it's more the background, with better target visibility. For example, at Spanish Fork you are up on the side of a mountain with the ground falling away in front of the trap houses. The houses face NW with Lake Utah in the far background. The targets are in the blue sky almost as soon as they clear the house.
As a contrast, when I shot often a Mason MI years ago, the background was trees, and the targets were harder to pick up. At Vandalia it was hangars and the occasional airplane landing.
One of the worst backgrounds I've ever seen was out west, Mesquite NV. There was tall grass immediately in front of the house, a brushy creek bottom with geese about 100 yards out, and then a red clay hillside several hundred yards out with a Motocross race going on. Trying to pick out those orange biodegradable targets against the clay hillside with the motorcycles running about was tough, and even if you could, the targets quite often didn't break. There was at least one AA 27 AA shooter I know who went home that day when his singles score was well below 90. I had two handicap scores in the low 70s that weekend, and my scores weren't all that worse than everybody else's.