Nepotism is antithetical to merit. Merit is a foundational requirement for any group to be successful.

However, some groups (White people) are capable of being understandably nepotistic (like raising your sons to follow in your footsteps in whatever profession you're in, passing on your inheritance to your offspring, or preferring the people of your own community than that of outsiders). However, the above exceptions to nepotism can easily, and often better, be described by other traits than "nepotism", as they're logical behaviors for healthy people and communities to keep, so that they remain healthy. Nepotism, generally speaking, is what happens when people entirely eschew merit, usually for the purposes of retaining undue power, purely for power's sake, and such people are usually corrupt and destructive to the people around them, hurting whatever group they're a part of. Whereas healthy "nepotism" improves whatever group they're a part of.

This isn't really a refutation of what you said, just an exploration of it, as there are other considerations.