Apple is the largest company in the world, but it could lose its crown to a fast-growing tech giant that has been outperforming the iPhone maker.Apple (AAPL -0.76%) is the most valuable company in the world right now with a market cap of $3.4 trillion. But a closer look at the company's recent financial performance indicates that it is finding it difficult to put its growth into a higher gear.For instance, in the third quarter of fiscal 2024 (which ended on June 29), Apple's revenue increased just 5% year o ...