How many yearly events are drawing tens of thousands in cities? About 15% of the US runs regularly per stats, cardio is even more because cycling is also huge.

Of course cardio is unpleasant to most people, 73% of the US is overweight or obese. I'm saying for healthy individuals with a small modicum of fitness (like their bodies were evolutionarily designed to do, we are the animal kingdom's top long distance runner after all), cardio is generally enjoyable.