I think this discussion is about the contributing factors in economic equality. "Decisions" is just one of the possible contributing factors.

I was trying to use an obvious (no maths needed) example to make the point that access to capital is another, more powerful contributing factor.

The trust fund was a much easier way to make the point than if I give you a spreadsheet about people whose parents pay for their college versus those with student loans, or people whose parents own homes they can live in versus those who don't, people with access to college and people without etc etc etc.

There's not all that much churn between those with access to capital and those without.