Why is white-collar employment more significant in a postindustrial society than in a industrial society?

White-Collar is a term that refers to employees that wear suit and tie, and usually work from a desk job, while excluding physical labor. These desk jobs are everywhere in a postindustrial society which focuses on the use of technology and providing goods and services to the consumers, usually through online routes. While industrial societies focus on hard labor and mass production of goods and services through manufacturing assembly lines.