Real advancement in robotics began after WWII, and by the 1980s, many manual tasks in manufacturing and agriculture had been replaced by robots who could do the job better, faster, and cheaper. For the past thirty-plus years, a multitude of industries has added robotic automation to improve production, efficiency, precision, and to control costs.
Meanwhile, the call center industry has relentlessly remained a business model reliant on human interaction. Sure, IVRs (Interactive Voice Response) and other interactive tools have been added that allow for greater efficiencies, but they are primarily used for simple tasks and have a limited scope of function. Attempts to teach computers to speak and process human language date back to the 1950s but until recently, computing power was just not significant enough to cross the divide (hat tip to Gordon Moore) to AI-driven natural language conversations.