Some of us will remember the old old International terminal, which, I believe, was where the United terminal is today. INTL got booted into the basement of the parking garage, as T4, when the old one got torn down before T5 was constructed. My history is a bit shaky here, others might have more precise recollections.

T4 was indeed a very, very grim affair. Even without shopping, T5 is world class by comparison. In any case, with a huge percentage of INTL depatures leaving from T1/3, most people never see the upper floor and rush through the lower level upon arrival.