I think the main reason not to go full-throttle into "vibes -> machine code" (to extrapolate past doing it in C) is because we have a history of building nested dolls of bounded error in our systems. We do that with the idea of file systems, process separation, call stacks, memory allocations, and virtual machines.

Now, it is true that vibes results in producing a larger quantity of lower-level code than we would stomach on our own. But that has some consequences for the resulting maintenance challenge, since the system-as-a-whole is less structured by its boundaries.

I think a reasonable approach when using the tools is to address problems "one level down" from where you'd ordinarily do it, and to allow yourself to use something older where there is historical source for the machine to sample from. So, if you currently use Python, maybe try generating some Object Pascal. If you use C++, maybe use plain C. If there were large Forth codebases I'd recommend targeting that since it breaks past the C boundary into "you're the operator of the system, not just a developer", but that might be the language that the approach stumbles over the most.