Some relationships are based on agreement, some are based on status. For example, parent/child, neighbors, and elementary teacher/student, army/draftee, law enforcement/citizen are status based. Others are completely based on agreement. Landlord/tenant. A lot are a mixture of the two, where the status is agreed on, and some of the obligations of the relationship are agreed, but a lot of the obligations may be assumed based on the status. boyfriend/girlfriend, Employer/employee.
So the trend over the years has been toward obligations being based on agreement. Husband & wife no longer has as many obligations built into the status itself. At one point in time, it was almost completely status based. And the obligations of a child to its parents (and vice versa) based simply on the relationship itself are vastly reduced.
So now I am pondering, in an ideal world, which relationship obligations are appropriately status based. Can we ever get to marriages meaning only that the people involved have agreed to something with nothing about the something assumed?