> So pointing to the safety is why it’s a circular argument.
You're confusing me. How about I explain my understanding of what makes things circular.
Generic hypothetical: Regulation requires a part. Cars put the part in because of regulation. Later, people amending the regulations consider something else that requires that part, and they justify it as having negligible cost because that part is already in cars. Because that part is there from regulation, it's to a strong extent regulation justifying itself, and it's circular.
Does your understanding of circularity differ from that?
Now, consider a variant: Regulation requires a part. But it doesn't matter because cars have that part anyway. Later, people amending the regulations consider something else that requires that part, and they justify it as having negligible cost because that part is already in cars. Because that part is not there from regulation, it's not regulation justifying itself, and it's not circular.
Does that make sense? You could imagine the part is "wheels" for the variant. Regulations that imply wheels are not using circular arguments when they say 'cars have wheels anyway, that's not a cost of this regulation'.