Why did it use present perfect tense, not just past tense?
We use the past simple tense for past events or actions which have no connection to the present. We use the present perfect for actions which started in the past and are still happening now or for finished actions which have a connection to the present. Ex: I have been friends with Julie for 10 years. (We're still friends). Ex: I was friends with Julie for 10 years. (We're no longer friends).