Ask: Can Apple continue the walled garden approach with device proliferation?

Apple's value is in supplying their customers with every smart device they need, and integrating them all. Right now, most people use just 1 or 2 devices, so Apple can manage building/marketing all of them. What happens when the average user interacts with 10 smart devices a day? 50? It seems that Apple will rapidly lose people from the garden as they fail to support the entire gadget experience.