Roughly 4.4% of the world's population lives in the USA. That still leaves 6.8 billion people.

There are many, many places where the option to ride without a helmet does wonders for cycling culture.

If we consider the entire world, the percentage of city dwellers drops to roughly 50%

I'm genuinely interested in the benefits of forgoing safety equipment that is readily available, easy to use, and proven to save lives.

Perhaps my experience is skewed because I almost exclusively do mountain biking. You couldn't pay me enough to ride on urban streets contending with cars.

The same benefits as forgoing a helmet when walking down the street.