You're massively underestimating just how much wiring is in a modern car. The car industry has been trying to move to 48V for decades to save money on wiring and Tesla just succeeded with Cybertruck. High consumption devices like electric power steering, electric A/C, and active anti-roll bars all require huge amperage to run at 12V and are only becoming more common on cars.

Car makers project big savings in moving to 48V and it's going to become a lot more common.