I don't think that's an accurate metaphor. Seatbelts are expressly a runtime solution to car crashes, whereas Python's type checking is a) only done during development (not even during build), and b) completely reliant on third-party tools.
If you're looking for a car analogy, I would suggest comparing Python type checking to installing speed cameras on the factory floor.
Because "all or nothing" is a bad idea.
If car crashes still kill people, why wear safety belts?
I don't think that's an accurate metaphor. Seatbelts are expressly a runtime solution to car crashes, whereas Python's type checking is a) only done during development (not even during build), and b) completely reliant on third-party tools.
If you're looking for a car analogy, I would suggest comparing Python type checking to installing speed cameras on the factory floor.
The analogy would be mandatory inspections of certain components or manufacturing processes to see that rules and specs are followed while assembling.