Interesting discussion.

Sailing is probably the most complex sport on Earth, so we can not focus on a single "key" feature that guarantees victories.

A great sailor has to excell in hydrodinamics, aerodynamics, resistance of materials, engineering, practical lamination, composites, maintenance, cleaning, sanding, sewing, legal matters, waves, meteorology, navigation, electronics, physical education, reflexes, teamworking, leadership, organization, planing, cooking, marketing, sales and more. Even luck plays an important part.

It is unlikely that any human being is talented in ALL this. If it ever happens, the talents will not be all at the same level. As a consequence, very talented sailors also need to train to improve his (many) relatively weaker talents.