AI is glorified autocomplete. Look at what happens when AI tries its hand at writing legal briefs, and you'll understand why it cannot possibly replace software developers.
At the same time, even if you have access to proper context like if your model can engage with Lexis or WestLaw via tool-use, surfacing appropriate matches from caselaw requires more than just word/token matching. LLMs are statistical models that tend to reduce down to the most likely answer. But, typically, in the context of a legal brief, a lawyer isn't attempting to find the most likely answer or even the objectively correct answer, they are trying to find relevant precedent with which they can make an argument that supports the position they are trying to advance. An LLM by its nature can't do that without help.
Where you're right, then, is that law and software engineering have a lot in common when it comes to how effective baseline LLM models are. Where you're wrong is in calling them glorified auto-complete.
In the hands of a novice they will, yes, generate plausible but mostly incorrect or technically correct but unusable in some way answers. Properly configured with access to appropriate context in the hands of an expert who understands how to communicate what they want the tool to give them? Oh that's quite a different matter.
But that's the whole point. You can't fit an entire legal database into the context, it's not big enough. The fact that you have to rely on "context is everything" as a cope is precisely why I'm calling them a glorified autocomplete.