Each variety tastes the same (a golden delicious apple tastes like other golden delicious apples). The grafting does that among other things "Maintain consiste

Each variety tastes the same (a golden delicious apple tastes like other golden delicious apples). The grafting does that among other things "Maintain consistency". A hardy root system that you mention is one. I started looking into it because my dad has a giant apple tree thats much bigger than the ones I've seen in an orchard, but the apples taste surprisingly bitter. I guess another reason they like grafting is the trees stay smaller and its easier to pick the fruit.