Except the huge part that you're missing is that, when they do a swap or a replacement at an Apple store, they don't just throw away the hardware. They send it back to be disassembled, tested, and remanufactured. They re-use a vast amount of these components and all of their warranty devices are remanufactured from good, tested components that were pieced out of larger components. Just because they don't do individual component repairs at the stores doesn't mean it's unfixable hardware.
Except the huge part that you're missing is that, when they do a swap or a replacement at an Apple store, they don't just throw away the hardware. They send it back to be disassembled, tested, and remanufactured. They re-use a vast amount of these components and all of their warranty devices are remanufactured from good, tested components that were pieced out of larger components. Just because they don't do individual component repairs at the stores doesn't mean it's unfixable hardware.