Tim Cook is stepping down as Apple CEO on September 1 after growing the company's market value from $350 billion to $4 trillion over 15 years — primarily through operational excellence, supply chain management, and financial discipline rather than breakthrough product innovation. Unlike Steve Jobs, who drove Apple through revolutionary design and technology, Cook succeeded by making Apple run like a well-oiled machine while capitalizing on existing products like the iPhone. His legacy reflects a fundamental shift in how the world's most valuable company creates value: not through innovation, but through execution and shareholder returns.