The thing is that the parallels you are drawing is for things that is very explicitly not the source of the code, but exists alongside it. Code is the ultimate truth. Documentation is a more humane way to describe it. Tests are there to ensure that what is there is what we want. And linters are there to warn us of specific errors. None of these create code.

To go from spec to code requires a lot of decisions (each introducing technical debt). Automating the process remove control over those decisions and over the ultimate truth that is the code. But why can't the LLM retains the trace of the decisions so that it presents control point to alter the results. Instead, it's always a rewrite from scratch.