LLMs are capable of producing junk, and they are capable of writing decent code. It is up to the operator to use them properly.
The prevailing research suggests this is not quicker than just writing it in the first place.
To put it another way, ask what code an LLM can maintain, not just what code a human (of whatever experience level) can maintain.
* in the original sense, no human feedback at any point
I'd say spending at least a quarter of my vibe coding time on refactoring + documentation refresh to ensure the codebase looking impeccable is the only way my projects can work at all long term. We don't want to confuse the coding agent.