What is iOS tightly integrated with the hardware?

Think of an iPhone as a custom-built house where the operating system and the hardware are built by the same architect.

Most computers use parts from different stores, like buying a fridge from one shop and a stove from another. They have to learn to talk to each other, which takes extra energy. Apple designs both the brain (the processor) and the body (the screen, camera, sensors). Because they are made to work together, they communicate without confusion.

Imagine a soccer team where every player knows the coach’s playbook by heart. When