choice has no say in this. Choice means that you have the luxury to choose between more than one.
btw - you forgot to mention Karachi - which is the biggest city in Pakistan by all standards, there is no seat belt law there. However back to your question.
You are assuming that all car owners in Pakistan are educated.. have you recently met car owners in Pakistan. The sheeple (aka hujoom) who are lining up at sarviss teyshun to drown their cars or putting scrapped parts for repairs are nowhere near educated, Yet they own cars.
Seat belts used to be a choice in the past - hence many manufacturers sometimes only offered it as upgrades - e.g. corolla E70, E80 imported into Pakistan had no seat belts. Pakistan did not and still does not have it mandated federally.
However in countries where this is mandated federally - cars are not allowed to clear customs if they are void of belts.
your argument is quite invalid - you are siding with choice and requirements as you please.