There is a long-standing argument that people tend to hire those who look like them or those they easily relate to. This tendency reflects a well-documented human bias. In practice, access to jobs and positions of influence is often shaped by two factors:
a) Who you know, and how closely you resemble those already in the system
b) How capable you are

I think both factors exist in most organisations and the challenge is how to balance between them. A system that claims to value merit must ensure that capability carries greater weight than familiarity or resemblance. And opportunity should be determined primarily by how good someone is at the work, rather than by who they know or what they look like. That is the standard a merit-based system should meet.