The better metric would be correlating someone's socio-economic class at birth with deltas in wealth later in life. I'd be very surprised to find a radically different conclusion, but at the least it'll give us more actionable data. After all, trying to eradicate advantages-by-birth might be the most futile exercise in human history but maybe we can adjust for them as we grow to learn more about the statistical relationship.
A 100% inheritance tax would be nigh-impossible in practical terms but in abstract it would go a long way to further the end of creating a society more closely based on merit.
I'm sure there are literal lapdogs endowed with more net worth and power than I have by their owners.
edit: I should clarify that wealth is not correlated with gene quality or fitness, but it may follow familial/social/emotional connections of the wealthy that seem to point to a "good lineage". Case in point: royal families
Inheritance, assuming the families have on average more than one child in each generation and the split is even, dilutes a family's fortunes over time. It would be correct to point out that the rules of some dynasties take this into account (head vs. branch families) and prevent this.
Even for myself, I used to do grunt work in a factory. Now I work from home at a cushy software job thanks to things I obtained here. Maybe I won't ever make billions, or become the next Elon Musk, but I'm happy enough just to celebrate my own successes and work to improve my own lot in life.