But many, perhaps most, parsers and serializers for CSV are not compliant with RFC 4180.
RFC 4180 is not an official standard. The text of the RFC itself states:
> This memo provides information for the Internet community. It does
> not specify an Internet standard of any kind.
CSVs existed long before that RFC was written, and it is more a description of CSVs that are somewhat portable, not a definitive specification.