This is “luck” of a most pernicious kind. When one person is given a job because of who they know, someone else misses out on that job because they didn’t know the right people. If we were starting society from scratch, perhaps that would be alright. But we’re starting from a place in which most powerful positions are held by white men (like myself). And who are those privileged white men more likely to know? Other privileged white men. This might be most obvious in high-profile positions, but it starts early in the workforce, and is compounded over time.
The three words with more influence over our national life than any others remain who you know. “Luck” is one word for this. “Systematic discrimination” would be more accurate.