I would suggest that no city and no country has benefited from hosting the Olympics to the degree that Tokyo and Japan did in 1964. It was just as television was proliferating, and showed the world a modern Japan, no doubt influencing people's opinions when it came time to purchase Japanese-made products.
This year's Olympics could easily be the least beneficial of all Olympics, but despite empty seats, they're going on. As you watch this video, the archery and aquatic venues (3:45-3:53) are a few hundred meters south of our apartment.
