Let's say my healthcare provider's name is John Doe. He's in my contacts list with "Doctor" as a prefix. If I wanted to call or text him using Siri, I'd have to say, "Text John Doe" because "Text Doctor Doe" won't work. He may not be the only person with that prefix in my contacts list, and telling Siri that he's my doctor means every time I say "Text Doctor X," Siri will think I want to text Dr. Doe.
The only workaround is to add "Doctor Doe" as his nickname.
The only workaround is to add "Doctor Doe" as his nickname.