There are quite a few, including flavor, nutritional value, and the ability to blend them.
You might be surprised to learn that you can improve the flavor of some nuts by soaking them. Almonds and walnuts, in particular, benefit from being allowed to sit in cold water for a while.
Soaking the nuts can make them easier to chew, and surprisingly, this can increase their nutritional value.
Because you are reducing the quantities of antinutrients, you may find that the nuts are easier on your stomach.