To say that risk capacity is the "real" source of inequality is simply incorrect.

There are plenty of people at or below poverty level who have little/no aversion to risk - it's just that the high-stakes gambles accessible to them are of a different nature than those accessible to a person of middle/upper class.

Risks with high rewards associated with impoverished people:

  - Theft/robbery

  - Scams/fraud

  - Selling drugs/other illicit items

Risks with high rewards associated with the middle/upper class:

  - Investing (stocks, crypto)

  - Quitting your job to start a business

For the impoverished, the consequences and chances of things going awry are stronger than a person of middle/upper class, yet they do pursue those risks, likely at a higher rate than the upper/middle class pursues the risks listed for them.