I find it hard to imagine that if you're struggling to attain your own bare necessities you're going to have the energy or wiggle room to generate more wealth (e.g. to start a business)

But why are they struggling so? Is it simply because of a lack of money?

Good point. They're struggling due to having unmet basic needs. Since money provides almost no nutritional value I can't see how it would help them. You've enlightened me; I'm now a social darwinist. /s

> This implies that they're not wealthy because they don't have access, would you agree? Is it possible they're not wealthy because of some other reason?

Two things:

(1) opportunity for wealth building is only one, of many, reasons for BI, and (2) It is certain that for some portion of the population, additional income will not be sufficient for notably better wealth building. But its equally certain that some portion of the population that would net benefit from BI is held back solely by short-term resources.