Other sports may require more technical skills, but they are only sports, after all. Running is a survival skill, a “sport” that existed before rules or competition (other than the competition to survive). It’s already inside us when we’re born, we need it because our ancestors found it so useful. We can’t be as healthy sitting around, long distances are a human specialty, we’re slow in a sprint. All things being equal, a human will wear down any other animal over a long distance. They don’t have a chance; we can eat & drink without stopping, it’s no accident.