A single part failure can easily cause a car to become completely undrivable, whereas a surprisingly amount can go wrong with human body and it works more or less the same.
Not enough fuel and a car stops. It's completely binary, either you enough gas to go, or you can't go. For a human there is an incredible range of failure modes for not having enough fuel. Humans can survive an absurdly long time when they are 'empty' of food.
However once that human body does fail, it's over. Additionally all parts of it collapse together.
A car is more or less the sum of it's parts. You can take each individual part and take it off and reuse it, like wise each failing impacts primarily it self. The engine can go find with a flat tire, you can use the headlights on car with no gas and no wheels until the batteries fall out. When an essential component for driving the car fails, all of the other components are still useful. This also means that any piece that is necessarily for the car to drive causes complete failure for the system when it fails. But it also means you can restore the system trivially by repairing a single part.
The human body is more than the sum of it's parts. You can't trivially remove or replace parts. The upside is it is wildly resistant to failure. You can lose an eye and still see, you can lose huge parts of the brain and still function, you can damage a leg running a marathon and still find a way to finish rather quickly, the entire system can be under attack by an invader and automatically defend it self.
But there are limit and when they are cross the entire system fails completely and irreversibly. And in this sense they do collapse faster because once that limit is crossed the system rapidly starts to fail and can never be restored.