Ill give you a hint: JPMC owns one of the largest buildings in the United States, second only to the Pentagon. Their Columbus location is a multi-mile long, 6 story, repurposed Mall. And thats just one of 8 Non-Branch locations they use in Columbus.
Know what's a good idea? Taking the two most important freeways in the city and having their on and off ramps overlap, and it's for only 200 feet total. Won't cause any traffic
Shopping malls tend to have choke points where the rapidly flowing road traffic transitions to more random car park traffic. Not a problem if a few thousand people are coming and going as they please throughout the day but thousands of people arriving together at 9:00 and leaving together at 17:00... they're just not designed for that sort of thing.
It's mostly due to the sheer amount of people who work in the building. The building holds over 10k employees. Problem is, everyone wants to park near their office space so they dont have to walk a mile or two to get to the other side of the building. So it gets cluttered very quickly around key lots.
Also, there's no parking garages. It was a flat lot until a few yesra ago. Now its a flat lot with a second story.