A family physician can diagnose within the family the root cause of certain disease and the treatment given is quicker and more concentrated.
Usually if a patient visits a doctor who is not their family physician, they would ask the patient for the family history to understand the root cause for any disorder or disease or to know why certain parameters are not in place.
This is because most of the health issues run in the genes of the patient making it easy for the doctor to make an informed decision about the cause, diagnosis and treatment for the patient.
In the advancement of science and technology and even in the field of pharmaceuticals, knowing the family history, the physician makes the right choice of treatment and medication for the patient knowing what’s best for the family and what kind of medications they are allergic to etc.