Cars use many more off the shelf parts, they have far easier supply chains to tap into.
Designing and building the CPU, GPU, camera systems, neural chip/software, touchscreen, FaceID, etc. All of these components require way more competence to build than any single part of an electric car using an off the shelf computer.
Cars have more parts, but they are dramatically bigger, less intensely complex, less intensely integrated. Just the CPU alone of a phone puts an entire electric engine to shame in terms of difficulty of engineering.
So it’s an interesting comparison. But I’d put money on Apple making a great car before Tesla made a great computer.