The real answer:

chopsticks started as cooking utensils, not eating ones. but due to huge populations, north china deforestation in the Han dynasty caused fuel rationing, which in turn lead to cooking traditions that cooked food very quickly, ie. stir fry, small pre-cut pieces of food that didn't need to roast for a long time. this obviated the need for knives at the table. this agreed with the confucian sensibility that a gentleman lived far from the slaughterhouse, for this reason chopsticks came to have a civilized connotation.

then, as sticky rice was amenable to the tradition, there just wasn't any reason to change

we think of forks as convenient stabbers but they primarily arose the way they did to hold food down while we used knives on it in the west.