honestly, i believe this is more about basic human nature. Tell me, who are people going to take more seriously at first glance. Someone who shows up to a seminar with a bed head and a crappy physique, or a person who takes care of their body, makes sure he looks well. But at the end, the product is what matters.

Definitely agree the product is what matters, but it (likely) helps to either be physically attractive or confident, or both, conveying to investors, customers and whomever else to offer their time and attention to listen to you.