Failing -> homeless and starving is a failure mode at the level of the individual. That’s not good, but failure modes of the entire structure are higher priority and the two don’t really compare apples to apples. Capitalism (absent corruption) is actually sort of cleverly recursive there because financial destitution by definition cannot affect producers of vital goods, because the act of producing vital goods is precisely what is rewarded by the system. So at least what you mentioned cannot result in systemic failure from a mechanistic point of view, only an individual level failure (which isn’t to say that the individual is “to blame”, I am not talking moralistically, just that it affects individuals and not the entire structure).
On first paragraph, okay how does that scale though. Who does the actual work of producing things people need to live, and how do we make sure that enough people keep doing that specifically, even across plausible variable configurations such as “birth rate increases because people have more free time which means now you need more farming” etc.
We need to characterize these dynamics, wouldn’t you say? Have you thought about it, or are you satisfied by hand waving?