Thanks for reading and taking the time to respond, Peninah. That's actually not what I'm implying. I explicitly call out in the piece that even if people closely resemble each other, finding understanding can be difficult. Humanity is complicated and varied. However, the point is that the more removed you are from a person's experience the more challenging it is to understand that experience. There is no perfect here and as you point out truly representing everyone is impossible, but the more closely a team can resemble their user base, the higher likelihood there is of improved outcomes. My argument is that right now we frequently approach things as though empathy were a capability with a standardized output so we don't worry about representation on teams, but in reality proximity to a person's experience can dramatically change the accuracy of the outcome.
This variation in ability to empathize applies across genders and race, but in the societal system we operate in there is rarely an assumption that a team of women can design for men, but we frequently assume men can design for women. This is the whole basis of the asymmetrical distributon of power in the system.