That HBR article is poorly written and doesn’t support your comment. An example of poor quality - it mentions taller men are more likely to be CEOs, which implies causality but it offers no data or statistical analysis to support such a claim. A simple correlation may warrant investigation into causality but isn’t causal itself. Additionally that entire article is about CEOs and not “the rich”, which are two different categories. The CEO of a well-funded startup isn’t necessarily rich, for example.
Most wealthy people I’ve met may have had occasional luck but they’ve also had bad luck. But they are smarter, work harder (more intensely and longer hours), and put themselves in positions to encounter luck/opportunity with high frequency. By and large I’ve observed it to be a result of their innate traits and active decision making.
This recent cultural obsession with claiming that merit isn’t real and that meritocracies are a myth is itself a feel-good myth with little basis in reality. Every piece I’ve read with such claims either rests on dubious statistics or pontificates endlessly to ultimately state personal opinion.