Use the human brain as an example then. We don't really know how it works. I mean, we know there's neurotransmitters and neural pathways etc (much like nodes in a transformer), but we don't know how exactly intelligence or our thinking process works.

We're also pretty good at working around human 'hallucinations' and other inaccuracies. Whether it be someone having a bad day, a brain fart, or individual clumsiness. eg in a (bad) organisation, sometimes we do it with layers of reviews and committees, much like layers of LLMs judging each other.

I think too much is attached to the notion of "we don't understand how the LLM works". We don't understand how any complicated intelligence works, and potentially won't for the forseeable future.

More generally, a lot of society is built up from empirical understanding of black box systems. I'd claim the field of physics is a prime example. And we've built reliable systems from unreliable components (see the field of distributed systems).