One never appreciates the complexity of a machine until they are required to assemble or repair it. We conflate simplicity in appearance with simplicity of function, when in reality good design takes the incredibly complicated and makes it usable by a child. Just think about the parts and development it takes to build an iPad, yet a child has no problem navigating it.
An organization is made up the same way. We may not see the person who delivers the mail to each desk, but when the day comes that a check for thousands of dollars arrives, his job becomes essential. The maintenance worker may seem like a humble calling, until the building floods and only he knows what to do.
As a team within an organization, take pride in your function, but do not think your purpose is infinitely higher than another's. Each role plays an important part, and like a hand without fingers loses much of its usefulness, so an organization without all its parts slowly crumbles.