I never claimed systemd owns resolv.conf so the fact that the latter predates the former is irrelevant. resolv.conf is to be used to implement the resolver API.

I never claimed systemd owns resolv.conf so the fact that the latter predates the former is irrelevant. resolv.conf is to be used to implement the resolver API. Any tool which uses resolv.conf for any other purpose does so at its own peril.