Answer:
I am milky white and scares people.
People need me yet they give me away every day.
Deep, deep, do they go. Spreading out as they go. Never needing any air. They are sometimes as fine as hair.
I can be simple or I can be complex. I can be found in this riddle or in everyday life. I can be shapes or even colors.
Although it sounds like I work on a transportation device I actually work in a restaurant.
What never gets any wetter no matter how hard it rains?