alpine sports are very siloed in their events. They don't broadly care or follow other disciplines or other distances. So to find an apples to apples participation number you would have to see how many consistent competitive 400m hurdle runners there were for example and on down the list.

Because people look at athletes that they can relate to from a competition/difficulty standpoint. This is why Jordan is so revered. There are over 4 million gymnasts in the United states over 6 years old. The majority of them do some level of competition, and they all do the same events. Balance beam, floor, bars, vault. There is a shared understanding of all 4 million on what it takes and what it means to do what Biles does. While there are far more swimmers overall, the vast majority never do competitive swimming, and those that do are spread across many different distances, strokes, etc. Again, it's not recency bias. There are biases, and that's what I'm pointing out. But there isn't even a fixed definition on what greatest athlete even means.